Naphthyridine compounds and uses thereof

ABSTRACT

Naphthyridine compounds of formula (I). 
     
       
         
         
             
             
         
       
         
         
           
             variations thereof, and their use as inhibitors of HPK1 (hematopoietic kinase 1) are described. The compounds are useful in treating HPK1-dependent disorders and enhancing an immune response. Also described are methods of inhibiting HPK1, methods of treating HPK1-dependent disorders, methods for enhancing an immune response, and methods for preparing the naphthyridine compounds.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of International Patent Application No. PCT/CN2018/096781, filed Jul. 24, 2018, the contents of which are incorporated herein by reference in their entireties.

FIELD OF THE INVENTION

The present disclosure relates to naphthyridine compounds that are inhibitors of HPK1, compositions containing these compounds, and methods for enhancing an immune response and treating HPK1-dependent disorders such as cancer.

BACKGROUND OF THE INVENTION

The major treatment modalities used by oncologists to treat cancer are surgical resection, radiation therapy, and classical chemotherapeutic drugs. Unfortunately, surgical resection is not a viable option for many tumors or forms of cancers. Further, radiation therapy and chemotherapeutic drugs do not target only diseased cells and therefore, end up damaging healthy cells. Therapeutics that more specifically target tumor cells are being developed by taking advantage of tumor-specific expression of antigens or inappropriate overexpression or activation of specific proteins within tumor cells, but tumor cells are prone to mutation and can become resistant to drugs that specifically target tumor cells.

A new cancer treatment paradigm has emerged that harnesses the patient's own immune system to overcome immunoevasive strategies utilized by many cancers and to enhance anti-tumor immunity. One such strategy is to inhibit negative regulators of immune responses that normally function to maintain peripheral tolerance, allowing tumor antigens to be recognized as non-self entities.

The hematopoietic progenitor kinase 1 (HPK1) is an example of a negative regulator of dendritic cell activation, and T and B cell responses that can be targeted to enhance anti-tumor immunity. HPK1 is expressed predominantly by hematopoietic cells, including early progenitors. In T cells, it is believed that HPK1 negatively regulates T cell activation by reducing the persistence of signaling microclusters by phosphorylating SLP76 at Ser376 (Di Bartolo et al. (2007) JEM 204:681-691) and Gads at Thr254, which leads to the recruitment of 14-3-3 proteins that bind to the phosphorylated SLP76 and Gads, releasing the SLP76-Gads-14-3-3 complex from LAT-containing microclusters (Lasserre et al. (2011) J Cell Biol 195(5):839-853). HPK1 can also become activated in response to prostaglandin E2, which is often secreted by tumors, contributing to the escape of tumor cells from the immune system.

BRIEF SUMMARY OF THE INVENTION

Disclosed are naphthyridine compounds that are inhibitors of HPK1, compositions containing these compounds, and methods for enhancing an immune response and treating HPK1-dependent disorders such as cancer.

In one aspect, provided is a compound of Formula (I), or any variation thereof, or a salt thereof (e.g., a pharmaceutically acceptable salt thereof), as detailed herein. Also provided is a pharmaceutical composition comprising a compound of Formula (I), or any variation thereof detailed herein, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier or excipient.

In another aspect, provided is a method for inhibiting HPK1, comprising contacting HPK1 in a subject with an effective amount of the compound of Formula (I), or any variation thereof detailed herein, or a pharmaceutically acceptable salt thereof. Also provided is a method for enhancing an immune response in a subject in need thereof, comprising administering to the subject an effective amount of the compound of Formula (I), or any variation thereof detailed herein, or a pharmaceutically acceptable salt thereof.

Further provided is a method for treating a HPK1-dependent disorder, comprising administering to a subject in need thereof an effective amount of the compound of Formula (I), or any variation thereof detailed herein, or a pharmaceutically acceptable salt thereof. In some embodiments, the subject is a human. In some embodiments, the HPK1-dependent disorder is a cancer, for example, colorectal cancer, melanoma, non-small cell lung cancer, ovarian cancer, breast cancer, pancreatic cancer, a hematological malignancy, and a renal cell carcinoma. In some embodiments, the method further comprises administering a chemotherapeutic agent to the subject.

Also provided is a compound of Formula (I), or any variation thereof detailed herein, or a pharmaceutically acceptable salt thereof, for use in a method of inhibiting HPK1, enhancing an immune response, or treating a HPK1-dependent disorder such as cancer.

Also provided is use of a compound of Formula (I), or any variation thereof detailed herein, or a pharmaceutically acceptable salt thereof, in a method detailed herein (e.g., treatment of a HPK1-dependent disorder such as cancer.

Also provided is use of a compound of Formula (I), or any variation thereof detailed herein, or a pharmaceutically acceptable salt thereof, for the manufacture of a medicament for use in a method detailed herein (e.g., treatment of a HPK1-dependent disorder such as cancer.

Also provided is a kit for treating a HPK1-dependent disorder, the kit comprising a pharmaceutical composition comprising a the compound of Formula (I), or any variation thereof detailed herein, or a pharmaceutically acceptable salt thereof; and instructions for use.

In another aspect, provided is a method of making a compound of Formula (I) or any variation thereof. Also provided are compound intermediates useful in synthesis of a compound of Formula (I), or any variation thereof.

DETAILED DESCRIPTION OF THE INVENTION

Disclosed herein, are compounds of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), and pharmaceutical compositions thereof that are inhibitors or modulators of HPK1 (hematopoietic progenitor kinase 1). As such, the compounds and compositions are useful in treating diseases and disorders mediated by HPK1. An example of a method of treating is in the case of a subject who is suffering from cancer. The compounds can be used not only to combat cancer, but can also advantageously be used to enhance an immune response in a subject in need thereof.

The presently disclosed subject matter will now be described more fully hereinafter. However, many modifications and other embodiments of the presently disclosed subject matter set forth herein will come to mind to one skilled in the art to which the presently disclosed subject matter pertains having the benefit of the teachings presented in the foregoing descriptions. Therefore, it is to be understood that the presently disclosed subject matter is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. In other words, the subject matter described herein covers all alternatives, modifications, and equivalents. In the event that one or more of the incorporated literature, patents, and similar materials differs from or contradicts this application, including but not limited to defined terms, term usage, described techniques, or the like, this application controls. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in this field. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety.

Definitions

“Alkyl” as used herein refers to a saturated linear (i.e. unbranched) or branched univalent hydrocarbon chain or combination thereof, having the number of carbon atoms designated (i.e., C₁₋₁₀ means one to ten carbon atoms). Particular alkyl groups are those having 1 to 20 carbon atoms (a “C₁₋₂₀ alkyl”), having a 1 to 8 carbon atoms (a “C₁₋₈ alkyl”), having 1 to 6 carbon atoms (a “C₁₋₆ alkyl”), having 2 to 6 carbon atoms (a “C₂₋₆ alkyl”), or having 1 to 4 carbon atoms (a “C₁₋₄ alkyl”). Examples of alkyl group include, but are not limited to, groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, isobutyl, sec-butyl, homologs and isomers of, for example, n-pentyl, n-hexyl, n-heptyl, n-octyl, and the like.

“Alkenyl” as used herein refers to an unsaturated linear (i.e., unbranched) or branched univalent hydrocarbon chain or combination thereof, having at least one site of olefinic unsaturation (i.e., having at least one moiety of the formula C═C) and having the number of carbon atoms designated (i.e., C₂₋₁₀ means two to ten carbon atoms). The alkenyl group may be in “cis” or “trans” configurations, or alternatively in “E” or “Z” configurations. Particular alkenyl groups are those having 2 to 20 carbon atoms (a “C₂₋₂₀ alkenyl”), having a 2 to 8 carbon atoms (a “C₂₋₈ alkenyl”), having 2 to 6 carbon atoms (a “C₂₋₆ alkenyl”), or having 2 to 4 carbon atoms (a “C₂₋₄ alkenyl”). Example of alkenyl group include, but are not limited to, groups such as ethenyl (or vinyl), prop-1-enyl, prop-2-enyl (or allyl), 2-methylprop-1-enyl, but-1-enyl, but-2-enyl, but-3-enyl, buta-1,3-dienyl, 2-methylbuta-1,3-dienyl, homologs and isomers thereof, and the like.

“Alkynyl” as used herein refers to an unsaturated linear (i.e. unbranched) or branched univalent hydrocarbon chain or combination thereof, having at least one site of acetylenic unsaturation (i.e., having at least one moiety of the formula C═C) having the number of carbon atoms designated (i.e., C₂₋₁₀ means two to ten carbon atoms). Particular alkynyl groups are those having 2 to 20 carbon atoms (a “C₂₋₂₀ alkynyl”), having a 2 to 8 carbon atoms (a “C₂₋₈ alkynyl”), having 2 to 6 carbon atoms (a “C₂₋₆ alkynyl”), having 2 to 4 carbon atoms (a “C₂₋₄ alkynyl”). Examples of alkynyl group include, but are not limited to, groups such as ethynyl (or acetylenyl), prop-1-ynyl, prop-2-ynyl (or propargyl), but-1-ynyl, but-2-ynyl, but-3-ynyl, homologs and isomers thereof, and the like.

“Alkylene” as used herein refers to the same residues as alkyl, but having bivalency. Particular alkylene groups are those having 1 to 6 carbon atoms (a “C₁₋₆ alkylene”), 1 to 5 carbon atoms (a “C₁₋₅ alkylene”), having 1 to 4 carbon atoms (a “C₁₋₄ alkylene”), or 1 to 3 carbon atoms (a “C₁₋₃ alkylene”). Examples of alkylene include, but are not limited to, groups such as methylene (—CH₂—), ethylene (—CH₂—CH₂—), propylene (—CH₂—CH₂—CH₂—), butylene (—CH₂—CH₂—CH₂—CH₂—), and the like.

“Cycloalkyl” as used herein refers to non-aromatic, saturated or unsaturated cyclic univalent hydrocarbon structures having the number of carbon atoms designated (i.e., (C₃₋₁₀ means three to ten carbon atoms). Cycloalkyl can consist of one ring, such as cyclohexyl, or multiple rings, such as adamantly, but excludes aryl groups. A cycloalkyl comprising more than one ring may be fused, spiro, or bridged, or combinations thereof. Particular cycloalkyl groups are those having from 3 to 12 annular carbon atoms. A preferred cycloalkyl is a cyclic hydrocarbon having from 3 to 8 annular carbon atoms (a “C₃₋₈ cycloalkyl”), or having 3 to 6 carbon atoms (a “C₃₋₆ alkynyl”). Examples of cycloalkyl include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohyxyl, 1-cyclohexenyl, 3-cyclohexenyl, cycloheptyl, norbomyl, and the like.

“Aryl” as used herein refers to an unsaturated aromatic carbocyclic group having a single ring (e.g., phenyl) or multiple condensed rings (e.g., naphthyl or anthryl) which condensed rings may or may not be aromatic. Particular aryl groups are those having from 6 to 14 annular (i.e., ring) carbon atoms (a “C₆₋₁₄ aryl”). An aryl group having more than one ring where at least one ring is non-aromatic may be connected to the parent structure at either an aromatic ring position or at a non-aromatic ring position. In one variation, an aryl group having more than one ring where at least one ring is non-aromatic is connected to the parent structure at an aromatic ring position.

“Heteroaryl” as used herein refers to an unsaturated aromatic cyclic group having from 1 to 14 annular (i.e., ring) carbon atoms and at least one annular heteroatom, including but not limited to heteroatoms such as nitrogen, phosphorus, oxygen and sulfur. A heteroaryl group may have a single ring (e.g., pyridyl, furyl) or multiple condensed rings (e.g., indolizinyl, benzothienyl) which condensed rings may or may not be aromatic. Particular heteroaryl groups are 5- to 14-membered rings having 1 to 12 annular (i.e., ring) carbon atoms and 1 to 6 annular (i.e., ring) heteroatoms independently selected from nitrogen, phosphorus, oxygen and sulfur; 5- to 10-membered rings having 1 to 8 annular carbon atoms and 1 to 4 annular heteroatoms independently selected from nitrogen, phosphorus, oxygen and sulfur; and 5-, 6- or 7-membered rings having 1 to 5 annular carbon atoms and 1 to 4 annular heteroatoms independently selected from nitrogen, oxygen and sulfur In one variation, heteroaryl include monocyclic aromatic 5-, 6- or 7-membered rings having from 1 to 6 annular carbon atoms and 1 to 4 annular heteroatoms independently selected from nitrogen, oxygen and sulfur. In another variation, heteroaryl includes polycyclic aromatic rings having from 1 to 12 annular carbon atoms and 1 to 6 annular heteroatoms independently selected from nitrogen, phosphorus, oxygen and sulfur. A heteroaryl group having more than one ring where at least one ring is non-aromatic may be connected to the parent structure at either an aromatic ring position or at a non-aromatic ring position. In one variation, a heteroaryl group having more than one ring where at least one ring is non-aromatic is connected to the parent structure at an aromatic ring position.

“Heterocycle”, “heterocyclic”, or “heterocyclyl” as used herein refers to a saturated or an unsaturated non-aromatic cyclic group having a single ring or multiple condensed rings, and having from 1 to 14 annular (i.e., ring) carbon atoms and from 1 to 6 annular (i.e., ring) heteroatoms, such as nitrogen, phosphorus, sulfur or oxygen, and the like. A heterocycle comprising more than one ring may be fused, spiro or bridged, or any combination thereof. In fused ring systems, one or more may be fused rings can be cycloalkyl. Particular heterocyclyl groups are 3- to 14-membered rings having 1 to 13 annular carbon atoms and 1 to 6 annular heteroatoms independently selected from nitrogen, phosphorus, oxygen and sulfur; 3- to 12-membered rings having 1 to 11 annular carbon atoms and 1 to 6 annular heteroatoms independently selected from nitrogen, phosphorus, oxygen and sulfur; 3- to 10-membered rings having 1 to 9 annular carbon atoms and 1 to 4 annular heteroatoms independently selected from nitrogen, phosphorus, oxygen and sulfur; 3- to 8-membered rings having 1 to 7 annular carbon atoms and 1 to 4 annular heteroatoms independently selected from nitrogen, phosphorus, oxygen and sulfur; and 3- to 6-membered rings having 1 to 5 annular carbon atoms and 1 to 4 annular heteroatoms independently selected from nitrogen, phosphorus, oxygen and sulfur. In one variation, heterocyclyl include monocyclic 3-, 4-, 5-, 6- or 7-membered rings having from 1 to 2, 1 to 3, 1 to 4, 1 to 5 or 1 to 6 annular carbon atoms and 1 to 2, 1 to 3 or 1 to 4 annular heteroatoms independently selected from from nitrogen, phosphorus, oxygen and sulfur. In another variation, heterocyclyl includes polycyclic non-aromatic rings having from 1 to 12 annular carbon atoms and 1 to 6 annular heteroatoms independently selected from nitrogen, phosphorus, oxygen and sulfur.

“Halo” or Halogen” refers to fluoro, chloro, bromo and/or iodo. Where a residue is substituted with more than one halogen, it may be referred to by using a prefix corresponding to the number of halogen moieties attached, e.g., dihaloaryl, dihaloalkyl, trihaloaryl etc. refer to aryl and alkyl substituted with two (“di”) or three (“tri”) halo groups, which may be but are not necessarily the same halo; thus 4-chloro-3-fluorophenyl is within the scope of dihaloaryl. An alkyl group in which each hydrogen is replaced with a halo group is referred to as a “perhaloalkyl.” A preferred perhaloalkyl group is trifluoroalkyl (—CF₃). Similarly, “perhaloalkoxy” refers to an alkoxy group in which a halogen takes the place of each H in the hydrocarbon making up the alkyl moiety of the alkoxy group. An example of a perhaloalkoxy group is trifluoromethoxy (—OCF₃).

“Carbonyl” refers to the group C═O.

“Thiocarbonyl” refers to the group C═S.

“Oxo” refers to the moiety ═O.

“Geminal” refers to the relationship between two moieties that are attached to the same atom. For example, in the residue —CH₂—CR^(x)R^(y)—, R^(x) and R^(y) are geminal and R^(x) may be referred to as a geminal R group to R^(y).

“Vicinal” refers to the relationship between two moieties that are attached to adjacent atoms. For example, in the residue —CHR^(x)—CHR^(y)—, R^(x) and R^(y) are vicinal and R^(x) may be referred to as a vicinal R group to R^(y).

“Optionally substituted” unless otherwise specified means that a group may be unsubstituted or substituted by one or more (e.g., 1, 2, 3, 4 or 5) of the substituents listed for that group in which the substituents may be the same or different. In one embodiment, an optionally substituted group has one substituent. In another embodiment, an optionally substituted group has two substituents. In another embodiment, an optionally substituted group has three substituents. In another embodiment, an optionally substituted group has four substituents. In some embodiments, an optionally substituted group has 1 to 2, 1 to 3, 1 to 4 or 1 to 5 substituents.

Use of the word “inhibitor” herein is meant to mean a molecule that inhibits activity of HPK1. By “inhibit” herein is meant to decrease the activity of the target enzyme, as compared to the activity of that enzyme in the absence of the inhibitor. In some embodiments, the term “inhibit” means a decrease in HPK1 activity of at least about 5%, at least about 10%, at least about 20%, at least about 25%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, or at least about 95%. In other embodiments, inhibit means a decrease in HPK1 activity of about 5% to about 25%, about 25% to about 50%, about 50% to about 75%, or about 75% to 100%. In some embodiments, inhibit means a decrease in HPK1 activity of about 95% to 100%, e.g., a decrease in activity of 95%, 96%, 97%, 98%, 99%, or 100%. Such decreases can be measured using a variety of techniques that would be recognizable by one of skill in the art, including in vitro kinase assays.

As used herein, a “HPK1 antagonist” or a “HPK1 inhibitor” is a molecule that reduces, inhibits, or otherwise diminishes one or more of the biological activities of HPK11 (e.g., serine/threonine kinase activity, recruitment to the TCR complex upon TCR activation, interaction with a protein binding partner, such as SLP76). Antagonism using the HPK1 antagonist does not necessarily indicate a total elimination of the HPK1 activity. Instead, the activity could decrease by a statistically significant amount including, for example, a decrease of at least about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 95% or 100% of the activity of HPK1 compared to an appropriate control. In some embodiments, the HPK11 antagonist reduces, inhibits, or otherwise diminishes the serine/threonine kinase activity of HPK1. In some of these embodiments, the HPK11 antagonist reduces, inhibits, or otherwise diminishes the HPK11-mediated phosphorylation of SLP76 and/or Gads. The presently disclosed compounds bind directly to HPK11 and inhibit its kinase activity.

By “specific antagonist” is intended an agent that reduces, inhibits, or otherwise diminishes the activity of a defined target greater than that of an unrelated target. For example, a HPK11 specific antagonist reduces at least one biological activity of HPK11 by an amount that is statistically greater than the inhibitory effect of the antagonist on any other protein (e.g., other serine/threonine kinases). In some embodiments, the IC₅₀ of the antagonist for the target is about 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, 5%, 1%, 0.1%, 0.01%, 0.001% or less of the IC₅₀ of the antagonist for a non-target. The presently disclosed compounds may or may not be a specific HPK11 antagonist. A specific HPK11 antagonist reduces the biological activity of HPK11 by an amount that is statistically greater than the inhibitory effect of the antagonist on any other protein (e.g., other serine/threonine kinases). In certain embodiments, the HPK11 antagonist specifically inhibits the serine/threonine kinase activity of HPK1. In some of these embodiments, the IC₅₀ of the HPK1 antagonist for HPK1 is about 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, 0.1%, 0.01%, 0.001%, or less of the IC₅₀ of the HPK1 antagonist for another serine/threonine kinase or other type of kinase (e.g., tyrosine kinase).

As used herein, “treatment” or “treating” is an approach for obtaining beneficial or desired results including clinical results. For purposes of this invention, beneficial or desired clinical results include, but are not limited to, one or more of the following: decreasing one or more symptoms resulting from the disease, diminishing the extent of the disease, stabilizing the disease (e.g., preventing or delaying the worsening of the disease), preventing or delaying the spread (e.g., metastasis) or the disease, delay or slowing the progression of the disease, ameliorating the disease state, providing a remission (whether partial or total) of the disease, decreasing the dose of one or more medications required to treat the disease, enhancing effect of another medication, delaying the progression of the disease, increasing the quality of life, and/or prolonging survival. Also encompassed by “treatment” is a reduction of pathological consequence of cancer. The methods of the invention contemplate any one or more of these aspects of treatment.

As used here, “delaying” the development of cancer means to defer, hinder, slow, retard, stabilize, and/or postpone development of the disease. This delay can be of varying lengths of time, depending on the history of the disease and/or subject being treated. As is evident to one skilled in the art, a sufficient or significant delay can, in effect, encompass prevention, in that the subject does not develop the disease. A method that “delays” development of cancer is a method that reduces probability of disease development in a given time frame and/or reduces the extent of the disease in a given time frame, when compared to not using the method. Such comparisons are typically based on clinical studies, using a statistically significant number of subjects. Cancer development can be detectable using standard methods, such as routine physical exams, mammography, imaging, or biopsy. Development may also refer to disease progression that may be initially undetectable and includes occurrence, recurrence, and onset.

As used herein, an “at risk” subject is a subject who is at risk of developing cancer. A subject “at risk” may or may not have detectable disease, and may or may not have displayed detectable disease prior to the treatment methods described herein. “At risk” denotes that a subject has one or more so-called risk factors, which are measurable parameters that correlate with development or cancer, which are described herein. A subject having one or more of these risk factors has a higher probability of developing cancer than a subject without these risk factor(s).

As used herein, by “combination therapy” is meant a therapy that includes two or more different compounds. Thus, in one aspect, a combination therapy comprising a compound detailed herein and another compound is provided. In some variations, the combination therapy optionally includes one or more pharmaceutically acceptable carriers or excipients, non-pharmaceutically active compounds, and/or inert substances.

As used herein, the term “effective amount” intends such amount of a compound of the invention which in combination with its parameters of efficacy and toxicity, should be effective in a given therapeutic form. As is understood in the art, an effective amount may be in one or more doses, i.e., a single dose or multiple doses may be required to achieve the desired treatment endpoint. An effective amount may be considered in the context of administering one or more therapeutic agents, and a single agent may be considered to be given in an effective amount if, in conjunction with one or more other agents, a desirable or beneficial results may be or is achieved. Suitable doses of any of the co-administered compounds may optionally be lowered due to the combined action (e.g., additive or synergistic effects) of the compounds. In various embodiments, an effective amount of the composition or therapy may (i) reduce the number of cancer cells); (ii) reduce tumor size; (iii) inhibit, retard, slow to some extent, and preferably stop cancer cell infiltration into peripheral organs; (iv) inhibit (e.g., slow to some extent and preferably stop) tumor metastasis; (v) inhibit tumor growth; (vi) prevent or delay occurrence and/or recurrence of a tumor; and/or (vii) relieve to some extent one or more of the symptoms associated with the cancer. In various embodiments, the amount is sufficient to ameliorate, palliate, lessen, and/or delay one or more of symptoms of cancer.

As is understood in the art, an “effective amount” may be in one or more doses, i.e., a single dose or multiple doses may be required to achieve the desired treatment endpoint. An effective amount may be considered in the context of administering one or more therapeutic agents, and a compound, or pharmaceutically acceptable salt thereof, may be considered to be given in an effective amount if, in conjunction with one or more other agents a desirable or beneficial result may be or is achieved.

A “therapeutically effective amount” refers to an amount of a compound or salt thereof sufficient to produce a desired therapeutic outcome (e.g., reducing the severity or duration of, stabilizing the severity of, or eliminating one or more symptoms of cancer). For therapeutic use, beneficial or desired results include, e.g., decreasing one or more symptoms resulting from the disease (biochemical, histologic and/or behavioral), including its complications and intermediate pathological phenotypes presenting during development of the disease, increasing the quality of life of those suffering from the disease, decreasing the dose of other medications required to treat the disease, enhancing effect of another medication, delaying the progression of the disease, and/or prolonging survival of patients.

A“prophylactically effective amount” refers to an amount of a compound, or pharmaceutically acceptable salt thereof, sufficient to prevent or reduce the severity of one or more future symptoms of cancer when administered to a subject who is susceptible and/or who may develop cancer. For prophylactic use, beneficial or desired results include, e.g., results such as eliminating or reducing the risk, lessening the severity of future disease, or delaying the onset of the disease (e.g., delaying biochemical, histologic and/or behavioral symptoms of the disease, its complications, and intermediate pathological phenotype presenting during future development of the disease).

It is understood that an effective amount of a compound or pharmaceutically acceptable salt thereof, including a prophylactically effective amount, may be given to a subject in the adjuvant setting, which refers to a clinical setting in which a subject has had a history of cancer, and generally (but not necessarily) has been responsive to therapy, which includes, but is not limited to, surgery (e.g., surgical resection), radiotherapy, and chemotherapy. However, because of their history of the cancer, these subjects are considered at risk of developing cancer. Treatment or administration in the “adjuvant setting” refers to a subsequent mode of treatment.

As used herein, “unit dosage form refers to physically discrete units, suitable as unit dosages, each unit containing predetermined quantity of active ingredient calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier or excipient. Unit dosage forms may contain a single or a combination therapy.

As used herein, the term “controlled release” refers to a drug-containing formulation or fraction thereof in which release of the drug is not immediate, i.e., with a “controlled release” formulation, administration does not result in immediate release of the drug into an absorption pool. The term encompasses depot formulations designed to gradually release the drug compound over an extended period of time. Controlled release formulation can include a wide variety of drug delivery systems, generally involving mixing the drug compound with carriers, polymers or other compounds having the desired release characteristics (e.g., pH-dependent or non-pH-dependent solubility, different degrees of water solubility, and the like) and formulating the mixture according to the desired route of delivery (e.g., coated capsules, implantable reservoirs, injectable solutions containing biodegradable capsules, and the like).

As used herein, by “pharmaceutically acceptable” or “pharmacologically acceptable” is meant a material that is not biologically or otherwise undesirable, e.g., the material may be incorporated into a pharmaceutical composition administered to a patient without causing any significant undesirable biological effects or interacting in a deleterious manner with any of the other components of the composition in which it is contained. Pharmaceutically acceptable carriers or excipients have preferably met the required standards of toxicological and manufacturing testing and/or are included on the Inactive Ingredient Guide prepared by the U.S. Food and Drug Administration.

In some embodiments, the salts of the compounds of the invention are pharmaceutically acceptable salts. “Pharmaceutically acceptable salts” are those salts which retain at least some of the biological activity of the free (non-salt) compound and which can be administered as drugs or pharmaceuticals to a subject. Such salts, for example, include: (1) acid addition salts, formed with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and the like; or formed with organic acids such as acetic acid, oxalic acid, propionic acid, succinic acid, maleic acid, tartaric acid and the like; (2) salts formed when an acidic proton present in the parent compound either is replaced by a metal ion, e.g., an alkali metal ion, an alkaline earth ion, or an aluminum ion; or coordinates with an organic base. Acceptable organic bases include ethanolamine, diethanolamine, triethanolamine and the like. Acceptable inorganic bases include aluminum hydroxide, calcium hydroxide, potassium hydroxide, sodium carbonate, sodium hydroxide, and the like. Pharmaceutically acceptable salts can be prepared in situ in the manufacturing process, or by separately reacting a purified compound of the invention in its free acid or base form with a suitable organic or inorganic base or acid respectively, and isolating the salt thus formed during subsequent purification.

The term “excipient” as used herein means an inert or inactive substance that may be used in the production of a drug or pharmaceutical, such as a tablet containing a compound of the invention as an active ingredient. Various substances may be embraced by the term excipient, including without limitation any substance used as a binder, disintegrant, coating, compression/encapsulation aid, cream or lotion, lubricant, solutions for parenteral administration, materials for chewable tablets, sweetener or flavoring, suspending/gelling agent, or wet granulation agent. Binders include, e.g., carbomers, povidone, xanthan gum, etc.; coatings include, e.g., cellulose acetate phthalate, ethylcellulose, gellan gum, maltodextrin, enteric coatings, etc.; compression/encapsulation aids include e.g. calcium carbonate, dextrose, fructose dc (dc—“directly compressible”), honey dc, lactose (anhydrate or monohydrate; optionally in combination with aspartame, cellulose, or microcrystalline cellulose), starch dc, sucrose, etc.; disintegrants include, e.g., croscarmellose sodium, gellan gum, sodium starch glycolate, etc.; creams or lotions include, e.g., maltodextrin, carrageenans, etc.; lubricants include, e.g., magnesium stearate, stearic acid, sodium stearyl fumarate, etc.; materials for chewable tablets include, e.g. dextrose, fructose dc, lactose (monohydrate, optionally in combination with aspartame or cellulose), etc.; suspending/gelling agents include, e.g., carrageenan, sodium starch glycolate, xanthan gum, etc.; sweeteners include, e.g., aspartame, dextrose, fructose dc, sorbitol, sucrose dc, etc.; and wet granulation agents include, e.g., calcium carbonate, maltodextrin, microcrystalline cellulose, etc. In some cases, the terms “excipient” and “carrier” are used interchangeably.

The term “subject” or “patient” refers to animals such as mammals, including, but not limited to, primates (e.g., humans), cows, sheep, goats, horses, dogs, cats, rabbits, rats, mice and the like. In certain embodiments, the subject is a human or a human patient.

The terms “abnormal cell growth,” “unregulated cell growth,” and “hyperproliferative disorder” are used interchangeably in this application. “Abnormal cell growth”, as used herein, unless otherwise indicated, refers to cell growth that is independent of normal regulatory mechanisms (e.g., loss of contact inhibition).

The term “cancer” refers to the condition in a subject that is characterized by unregulated cell growth, wherein the cancerous cells are capable of local invasion and/or metastasis to noncontiguous sites. As used herein, “cancer cells,” “cancerous cells,” or “tumor cells” refer to the cells that are characterized by this unregulated cell growth and invasive property. The term “cancer” encompasses all types of cancers, including, but not limited to, all forms of carcinomas, melanomas, blastomas, sarcomas, lymphomas and leukemias, including without limitation, bladder cancer, bladder carcinoma, brain tumors, breast cancer, cervical cancer, colorectal cancer, esophageal cancer, endometrial cancer, hepatocellular carcinoma, laryngeal cancer, lung cancer, osteosarcoma, ovarian cancer, pancreatic cancer, prostate cancer, renal carcinoma and thyroid cancer, acute lymphocytic leukemia, acute myeloid leukemia, ependymoma, Ewing's sarcoma, glioblastoma, medulloblastoma, neuroblastoma, osteosarcoma, rhabdomyosarcoma, rhabdoid cancer, and nephroblastoma (Wilm's tumor).

A “chemotherapeutic agent” is a chemical compound or biologic useful in the treatment of cancer. Examples of chemotherapeutic agents include alkylating agents such as thiotepa and cyclophosphamide (CYTOXAN®); alkyl sulfonates such as busulfan, improsulfan, and piposulfan; aziridines such as benzodopa, carboquone, meturedopa, and uredopa; ethylenimines and methylamelamines including altretamine, triethylenemelamine, trietylenephosphoramide, triethiylenethiophosphoramide and trimethylolomelamine; acetogenins (especially bullatacin and bullatacinone); delta-9-tetrahydrocannabinol (dronabinol, MARINOL®); beta-lapachone; lapachol; colchicines; betulinic acid; a camptothecin (including the synthetic analogue topotecan (HYCAMTIN®), CPT-11 (irinotecan, CAMPTOSAR®), acetylcamptothecin, scopolectin, and 9-aminocamptothecin); bryostatin; pemetrexed; callystatin; CC-1065 (including its adozelesin, carzelesin and bizelesin synthetic analogues); podophyllotoxin; podophyllinic acid; teniposide; cryptophycins (particularly cryptophycin 1 and cryptophycin 8); dolastatin; duocarmycin (including the synthetic analogues, KW-2189 and CB1-TM1); eleutherobin; pancratistatin; TLK-286; CDP323, an oral alpha-4 integrin inhibitor; a sarcodictyin; spongistatin; nitrogen mustards such as chlorambucil, chlornaphazine, cholophosphamide, estramustine, ifosfamide, mechlorethamine, mechlorethamine oxide hydrochloride, melphalan, novembichin, phenesterine, prednimustine, trofosfamide, uracil mustard; nitrosureas such as carmustine, chlorozotocin, fotemustine, lomustine, nimustine, and ranimnustine; antibiotics such as the enediyne antibiotics (e.g., calicheamicin, especially calicheamicin gamma1I and calicheamicin omegaI1 (see, e.g., Nicolaou et al., Angew. Chem Intl. Ed. Engl., 33: 183-186 (1994)); dynemicin, including dynemicin A; an esperamicin; as well as neocarzinostatin chromophore and related chromoprotein enediyne antibiotic chromophores), aclacinomysins, actinomycin, authramycin, azaserine, bleomycins, cactinomycin, carabicin, carminomycin, carzinophilin, chromomycinis, dactinomycin, daunorubicin, detorubicin, 6-diazo-5-oxo-L-norleucine, doxorubicin (including ADRIAMYCIN®, morpholino-doxorubicin, cyanomorpholino-doxorubicin, 2-pyrrolino-doxorubicin, doxorubicin HCl liposome injection (DOXIL®) and deoxydoxorubicin), epirubicin, esorubicin, idarubicin, marcellomycin, mitomycins such as mitomycin C, mycophenolic acid, nogalamycin, olivomycins, peplomycin, potfiromycin, puromycin, quelamycin, rodorubicin, streptonigrin, streptozocin, tubercidin, ubenimex, zinostatin, zorubicin; anti-metabolites such as methotrexate, gemcitabine (GEMZAR®), tegafur (UFTORAL®), capecitabine (XELODA®), an epothilone, and 5-fluorouracil (5-FU); folic acid analogues such as denopterin, methotrexate, pteropterin, trimetrexate; purine analogs such as fludarabine, 6-mercaptopurine, thiamiprine, thioguanine; pyrimidine analogs such as ancitabine, azacitidine, 6-azauridine, carmofur, cytarabine, dideoxyuridine, doxifluridine, enocitabine, and floxuridine; anti-adrenals such as aminoglutethimide, mitotane, trilostane; folic acid replenisher such as frolinic acid; aceglatone; aldophosphamide glycoside; aminolevulinic acid; eniluracil; amsacrine; bestrabucil; bisantrene; edatraxate; defofamine; demecolcine; diaziquone; elfornithine; elliptinium acetate; etoglucid; gallium nitrate; hydroxyurea; lentinan; lonidainine; maytansinoids such as maytansine and ansamitocins; mitoguazone; mitoxantrone; mopidanmol; nitraerine; pentostatin; phenamet; pirarubicin; losoxantrone; 2-ethylhydrazide; procarbazine; PSK® polysaccharide complex (JHS Natural Products, Eugene, Oreg.); razoxane; rhizoxin; sizofiran; spirogermanium; tenuazonic acid; triaziquone; 2,2′,2″-trichlorotriethylamine; trichothecenes (especially T-2 toxin, verracurin A, roridin A and anguidine); urethan; vindesine (ELDISINE®, FILDESIN®); dacarbazine; mannomustine; mitobronitol; mitolactol; pipobroman; gacytosine; arabinoside (“Ara-C”); thiotepa; taxoids, e.g., paclitaxel (TAXOL®), albumin-engineered nanoparticle formulation of paclitaxel (ABRAXANE™), and doxetaxel (TAXOTERE®); chloranbucil; 6-thioguanine; mercaptopurine; methotrexate; platinum analogs such as cisplatin and carboplatin; vinblastine (VELBAN®); platinum; etoposide (VP-16); ifosfamide; mitoxantrone; vincristine (ONCOVIN®); oxaliplatin; leucovovin; vinorelbine (NAVELBINE®); novantrone; edatrexate; daunomycin; aminopterin; ibandronate; topoisomerase inhibitor RFS 2000; difluorometlhylomithine (DMFO); retinoids such as retinoic acid; pharmaceutically acceptable salts, acids or derivatives of any of the above; as well as combinations of two or more of the above such as CHOP, an abbreviation for a combined therapy of cyclophosphamide, doxorubicin, vincristine, and prednisolone, and FOLFOX, an abbreviation for a treatment regimen with oxaliplatin (ELOXATIN™) combined with 5-FU and leucovovin.

Additional examples of chemotherapeutic agents include anti-hormonal agents that act to regulate, reduce, block, or inhibit the effects of hormones that can promote the growth of cancer, and are often in the form of systemic, or whole-body treatment. They may be hormones themselves. Examples include anti-estrogens and selective estrogen receptor modulators (SERMs), including, for example, tamoxifen (including NOLVADEX® tamoxifen), raloxifene (EVISTA®), droloxifene, 4-hydroxytamoxifen, trioxifene, keoxifene, LY117018, onapristone, and toremifene (FARESTON®); anti-progesterones; estrogen receptor down-regulators (ERDs); estrogen receptor antagonists such as fulvestrant (FASLODEX®); agents that function to suppress or shut down the ovaries, for example, leutinizing hormone-releasing hormone (LHRH) agonists such as leuprolide acetate (LUPRON® and ELIGARD®), goserelin acetate, buserelin acetate and tripterelin; anti-androgens such as flutamide, nilutamide and bicalutamide; and aromatase inhibitors that inhibit the enzyme aromatase, which regulates estrogen production in the adrenal glands, such as, for example, 4(5)-imidazoles, aminoglutethimide, megestrol acetate (MEGASE®), exemestane (AROMASIN®), formestanie, fadrozole, vorozole (RIVISOR®), letrozole (FEMARA®), and anastrozole (ARIMIDEX®). In addition, such definition of chemotherapeutic agents includes bisphosphonates such as clodronate (for example, BONEFOS® or OSTAC®), etidronate (DIDROCAL®), NE-58095, zoledronic acid/zoledronate (ZOMETA®), alendronate (FOSAMAX®), pamidronate (AREDIA®), tiludronate (SKELID®), or risedronate (ACTONEL®); as well as troxacitabine (a 1,3-dioxolane nucleoside cytosine analog); anti-sense oligonucleotides, particularly those that inhibit expression of genes in signaling pathways implicated in abherant cell proliferation, such as, for example, PKC-alpha, Raf, H-Ras, and epidermal growth factor receptor (EGF-R); vaccines such as THERATOPE® vaccine and gene therapy vaccines, for example, ALLOVECTIN® vaccine, LEUVECTIN® vaccine, and VAXID® vaccine; topoisomerase 1 inhibitor (e.g., LURTOTECAN®); an anti-estrogen such as fulvestrant; EGFR inhibitor such as erlotinib or cetuximab; an anti-VEGF inhibitor such as bevacizumab; arinotecan; rmRH (e.g., ABARELIX®); 17AAG (geldanamycin derivative that is a heat shock protein (Hsp) 90 poison), and pharmaceutically acceptable salts, acids or derivatives of any of the above.

Also included in the definition of “chemotherapeutic agent” are: (i) anti-hormonal agents that act to regulate or inhibit hormone action on tumors such as anti-estrogens and selective estrogen receptor modulators (SERMs), including, for example, tamoxifen (including NOLVADEX®; tamoxifen citrate), raloxifene, droloxifene, 4-hydroxytamoxifen, trioxifene, keoxifene, LY117018, onapristone, and FARESTON® (toremifine citrate); (ii) aromatase inhibitors that inhibit the enzyme aromatase, which regulates estrogen production in the adrenal glands, such as, for example, 4(5)-imidazoles, aminoglutethimide, MEGASE® (megestrol acetate), AROMASIN® (exemestane; Pfizer), formestanie, fadrozole, RIVISOR® (vorozole), FEMARA® (letrozole; Novartis), and ARIMIDEX® (anastrozole; AstraZeneca); (iii) anti-androgens such as flutamide, nilutamide, bicalutamide, leuprolide, and goserelin; as well as troxacitabine (a 1,3-dioxolane nucleoside cytosine analog); (iv) protein kinase inhibitors; (v) lipid kinase inhibitors; (vi) antisense oligonucleotides, particularly those which inhibit expression of genes in signaling pathways implicated in aberrant cell proliferation, such as, for example, PKC-alpha, Ralf and H-Ras; (vii) ribozymes such as VEGF expression inhibitors (e.g., ANGIOZYME®) and HER2 expression inhibitors; (viii) vaccines such as gene therapy vaccines, for example, ALLOVECTIN®, LEUVECTIN®, and VAXID®; PROLEUKIN® rIL-2; a topoisomerase 1 inhibitor such as LURTOTECAN®; ABARELIX® rmRH; (ix) anti-angiogenic agents such as bevacizumab (AVASTIN®, Genentech); and (x) pharmaceutically acceptable salts, acids and derivatives of any of the above.

In some embodiments, the chemotherapeutic agent is an immunotherapeutic agent. As used herein, an “immunotherapeutic agent” is a compound that enhances the immune system to help fight cancer, specifically or non-specifically. Immunotherapeutics include monoclonal antibodies and non-specific immunotherapies that boost the immune system, such as cytokines, interleukins (e.g., IL-2, IL-7, IL-12, IL-15, IL-21), interferons (e.g., IFN-α, IFN-β, IFN-γ), GM-CSF, thalidomide, (THALOMID®, Celgene), lenalidomide (REVLIMID®, Celgene), pomalidomide (POMALYST®, Celgene), imiquimod (ZYCLARA®, Valeant). Non-limiting examples of monoclonal antibodies that are useful as a chemotherapeutic agent include trastuzumab (HERCEPTIN®, Genentech), bevacizumab (AVASTIN®, Genentech), cetuximab (ERBITUX®, Bristol-Myers Squibb), panitumumab (VECTIBIX®, Amgen), ipilimumab (YERVOY®, Bristol-Myers Squibb), rituximab (RITUXAN®, Genentech), alemtuzumab (CAMPATH®, Genzyme), ofatumumab (ARZERRA®, Genmab), gemtuzumab ozogamicin (MYLOTARG®, Wyeth), brentuximab vedotin (ADCETRIS®, Seattle Genetics), ⁹⁰Y-labelled ibritumomab tiuxetan (ZEVALIN®, Biogen Idec), ¹³¹I-labelled tositumomab (BEXXAR®, GlaxoSmithKline), ado-trastuzumab emtansine (KADCYLA®, Genentech) blinatumomab (BLINCYTO®, Amgen), pertuzumab (PERJETA®, Genentech), obinutuzumab (GAZYVA®, Genentech), nivolumab (OPDIVO®, ) Bristol-Myers Squibb), pembrolizumab (KEYTRUDA®, Merck), pidilizumab (CureTech), MPDL3280A (described in WO2010/077634, herein incorporated by reference in its entirety), MDX-1105 (described in WO2007/005874, herein incorporated by reference in its entirety), and MEDI4736 (described in WO2011/066389 and US2013/034559, each of which is herein incorporated by reference in its entirety). Another useful immunotherapeutic agent is AMP-224 (described in WO2010/027827 and WO2011/066342, each of which is incorporated herein in its entirety).

Compounds

The compounds disclosed herein are compounds of Formula (I), or salts (e.g., pharmaceutically acceptable salts), solvates (e.g., hydrates), prodrugs, metabolites, or derivatives thereof. These compounds are useful inhibitors of HPK1.

In one aspect, provided is a compound of Formula (I):

or a salt (e.g., a pharmaceutically acceptable salt), solvate (e.g., hydrate), prodrug, metabolites or derivative thereof, wherein:

R¹ is hydrogen, halogen, hydroxyl, C₁₋₆ alkyl optionally substituted with halogen, C₃₋₄ cycloalkyl, or —O(C₁₋₆ alkyl) optionally substituted with halogen;

R² is a 5- to 14-membered heteroaryl optionally substituted with R¹⁰;

R³ is hydrogen, halogen, cyano, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, 3- to 14-membered heterocyclyl, or —OR⁷; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl and 3- to 14-membered heterocyclyl of R³ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

R⁴ is C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl, 3- to 14-membered heterocyclyl, halogen, cyano, —C(O)R⁶, —C(O)OR⁷, —C(O)NR^(8a)R^(8b), —OR⁷, —OC(O)R⁶, —OC(O)NR^(8a)R^(8b), —SR⁷, —S(O)R⁹, —S(O)₂R⁹, —S(O)₂NR^(8a)R^(8b), —P(O)R^(9a)R^(9b), —NR^(8a)R^(8b), —N(R⁸)C(O)R⁶, —N(R⁸)C(O)OR⁷, —N(R⁸)C(O)NR^(8a)R^(8b), —N(R⁸)S(O)₂R⁹, or —N(R⁸)S(O)₂NR^(8a)R^(8b); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R⁴ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰; each R⁶ is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁶ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

each R⁷ is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁷ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

each R⁸ is independently hydrogen or C₁₋₆ alkyl;

each R^(8a) and R^(8b) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(8a) and R^(8b) are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

-   -   or R^(8a) and R^(8b) are taken together with the nitrogen atom         to which they are attached to form a 4- to 12-membered         heterocyclyl optionally substituted with 1, 2, 3, 4 or 5         substituents independently selected from R¹⁰;

each R⁹ is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁹ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

each R^(9a) and R^(9b) is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl, 3- to 12-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(9a) and R^(9b) are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

-   -   or R^(9a) and R^(9b) are taken together with the phosphorus atom         to which they are attached to form a 4- to 12-membered         heterocyclyl optionally substituted with 1, 2, 3, 4 or 5         substituents independently selected from R¹⁰;

each R¹⁰ is independently oxo, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₉ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 12-membered heterocyclyl, halogen, cyano, —C(O)R^(a), —C(O)OR^(b), —C(O)NR^(c)R^(d), —OR^(b), —OC(O)R^(a), —OC(O)NR^(c)R^(d), —SR^(b), —S(O)R^(e), —S(O)₂R^(e), —S(O)(═NH)R^(e), —S(O)₂NR^(c)R^(d), —NR^(c)R^(d), —N(R^(f))C(O)R^(a), —N(R^(f))C(O)OR^(b), —N(R^(f))C(O)NR^(c)R^(d), —N(R^(f))S(O)₂R^(e), —N(R^(f))S(O)₂NR^(c)R^(d), or —P(O)R^(g)R^(h); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R¹⁰ are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R^(a) is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(a) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R^(b) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(b) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R^(c) and R^(d) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(c) and R^(d) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

-   -   or R^(c) and R^(d) are taken together with the nitrogen atom to         which they are attached to form a 4- to 12-membered heterocyclyl         optionally substituted with 1, 2, 3 or 4 substituents         independently selected from R¹¹;

each R^(e) is independently C₁₋₆ alkyl, C₃₋₉ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(e) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R^(f) is independently hydrogen or C₁₋₆ alkyl;

each R^(g) and R^(h) is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 12-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(g) and R^(h) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

-   -   or R^(g) and R^(h) are taken together with the phosphorus atom         to which they are attached to form a 4- to 12-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹¹;

each R¹¹ is independently oxo, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 8-membered heterocyclyl, halogen, cyano, —C(O)R^(a1), —C(O)OR^(b1), —C(O)NR^(c1)R^(d1), —OR^(b1), —OC(O)R^(a1), —OC(O)NR^(c1)R^(d1), —SR^(b1), —S(O)R^(e1), —S(O)₂R^(e1), —S(O)₂NR^(c1)R^(d1), —NR^(c1)R^(d1), —N(R^(f1))C(O)R^(a1), —N(R^(f1))C(O)OR^(b1), —N(R^(f1))C(O)NR^(c1)R^(d1), —N(R^(f1))S(O)₂R^(e1), —N(R^(f1))S(O)₂NR^(c1)R^(a1), or —P(O)R^(g1)R^(h1); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R¹¹ are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R^(a1) is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(a1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R^(b1) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(b1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R^(c1) and R^(d1) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(c1) and R^(d1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

-   -   or R^(c1) and R^(d1) are taken together with the nitrogen atom         to which they are attached to form a 4- to 8-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹²;

each R^(e1) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(c1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R¹ is independently hydrogen or C₁₋₆ alkyl;

each R^(g1) and R^(h1) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 8-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(g1) and R^(h1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

-   -   or R^(g1) and R^(h1) are taken together with the phosphorus atom         to which they are attached to form a 4- to 8-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹²;

each R¹² is independently oxo, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl, 3- to 6-membered heterocyclyl, halogen, cyano, —C(O)R^(a2), —C(O)OR^(b2), —C(O)NR^(c2)R^(d2), —OR^(b)2, —OC(O)R^(a2), —OC(O)NR^(c2)R^(d2), —S(O)₂R^(e2), —S(O)₂NR^(c2)R^(d2), —NR^(c2)R^(d2), —N(R^(f2))C(O)R^(a2), —N(R^(f2))C(O)OR^(b2), —N(R^(f2))C(O)NR^(c2)R^(d2), —N(R^(f2))S(O)₂R^(e2), —N(R^(f2))S(O)₂NR^(c2)R^(d2), or —P(O)R^(g2)R^(h2); wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R¹² are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R^(a2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R^(a2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R^(b2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl and 3- to 6-membered heterocyclyl of R^(b2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R^(c2) and R^(d2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl and 3- to 8-membered heterocyclyl of R^(c2) and R^(d2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

-   -   or R^(c2) and R^(a2) are taken together with the nitrogen atom         to which they are attached to form a 4- to 6-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹³;

each R^(e2) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R^(e2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R^(f2) is independently hydrogen or C₁₋₆ alkyl;

each R^(g2) and R² is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, 3- to 8-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, and 3- to 8-membered heterocyclyl of R^(g2) and R² are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

-   -   or R^(g2) and R^(h) are taken together with the phosphorus atom         to which they are attached to form a 4- to 6-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹³; and

each R¹³ is independently oxo, halogen, hydroxyl, —O(C₁₋₆ alkyl), cyano, C₁₋₆ alkyl or C₁₋₆ haloalkyl.

In one aspect, provided is a compound of Formula (I), or a salt (e.g., a pharmaceutically acceptable salt), solvate (e.g., hydrate), prodrug, metabolites or derivative thereof, wherein R¹, R³ and R⁴ are as defined above, and R² is a monocyclic 5- or 6-membered heteroaryl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰. In some embodiments, R² is a 5-membered heteroaryl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰. In some embodiments, R² is a pyrazolyl or a substituted pyrazolyl. In some embodiments, R² is a 5-membered heteroaryl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰, provided that R² is other than a pyrazolyl or a substituted pyrazolyl.

In one aspect, provided is a compound of Formula (I), or a salt (e.g., a pharmaceutically acceptable salt), solvate (e.g., hydrate), prodrug, metabolites or derivative thereof, wherein RI, R³ and R⁴ are as defined above, and R² is a polycyclic heteroaryl having the formula (a) or (b):

wherein the wavy line represents the attachment point to the parent structure,

Q is CR²⁰, NR²¹, N, O or S;

T is N or CR²²;

Z¹ and Z² are independently N or C, provided at least one of Z¹ and Z² is C;

T¹, T² and T³ are independently N or CR²³;

ring A and ring B are independently a C_(5-s) cycloalkyl or a 5- to 8-membered heterocycle having at least 3 ring-forming carbon atoms and 1, 2 or 3 ring-forming heteroatoms independently selected from the group consisting of N, P, O and S; wherein the C_(5-s) cycloalkyl and the 5- to 8-membered heterocycle are independently optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰; and wherein two substituents of the C₃₋₈ cycloalkyl or the 5- to 8-membered heterocycle, where present, optionally taken together form a spiro, fused or bridged cycloalkyl (e.g., C₃₋₆ cycloalkyl) optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰ or a sprio, fused or bridged heterocyclyl (e.g., 3- to 6-membered heterocyclyl) optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰; and

R²⁰, R²¹, R²² and R²³ are each independently hydrogen or R¹⁰.

In some embodiments, ring A or ring B is C₅₋₈ cycloalkyl optionally substituted with R¹⁰. In some embodiments, ring A or ring B is a 5- to 8-membered heterocycle (e.g., having at least 3 ring-forming carbon atoms and 1, 2 or 3 ring-forming heteroatoms independently selected from the group consisting of N, P, O and S) optionally substituted with R¹⁰. In some embodiments, two germinal substituents of the C₅₋₈ cycloalkyl or the 5- to 8-membered heterocycle, where present, optionally taken together with the atom to which they are attached form a spiro C₃₋₆ cycloalkyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰ or a sprio 3- to 6-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰. In some embodiments, two vicinal substituents of the C_(5-s) cycloalkyl or the 5- to 8-membered heterocycle, where present, optionally taken together with the atoms to which they are attached form a fused 5- or 6-membered heteroaryl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰ or a fused 5- or 6-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰.

In some embodiments of the compound of Formula (I), or a salt (e.g., a pharmaceutically acceptable salt), solvate (e.g., hydrate), prodrug, metabolites or derivative thereof, wherein R¹, R³ and R⁴ are as defined above, and R² is a polycyclic heteroaryl having the formula (a):

wherein the wavy line represents the attachment point to the parent structure, Q, T, Z¹, Z², and ring A are as defined above.

In some embodiments of the compound of Formula (I), or a salt (e.g., a pharmaceutically acceptable salt), solvate (e.g., hydrate), prodrug, metabolites or derivative thereof, wherein R¹, R³ and R⁴ are as defined above, and R² is a polycyclic heteroaryl having the formula (b):

wherein the wavy line represents the attachment point to the parent structure, T¹, T², T³, and ring B are as defined above. In some embodiments, at least one of T¹, T² and T³ is N.

In one aspect, provided is a compound of Formula (I):

or a salt (e.g., a pharmaceutically acceptable salt) thereof, wherein:

R¹ is hydrogen, halogen, hydroxyl, C₁₋₆ alkyl optionally substituted with halogen, C₃₋₄ cycloalkyl, or —O(C₁₋₆ alkyl) optionally substituted with halogen;

R² is (i) or (ii):

(i) a monocyclic 5- or 6-membered heteroaryl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰; or

(ii) a polycyclic heteroaryl having the formula (a) or (b):

-   -   wherein the wavy line represents the attachment point to the         parent structure,     -   Q is CR²⁰, NR²¹, N, O or S;     -   T is N or CR²²;     -   Z¹ and Z² are independently N or C, provided at least one of Z¹         and Z² is C;     -   T¹, T² and T³ are independently N or CR²³;     -   ring A and ring B are independently a C₅₋₈ cycloalkyl or a 5- to         8-membered heterocycle having at least 3 ring-forming carbon         atoms and 1, 2 or 3 ring-forming heteroatoms independently         selected from the group consisting of N, P, O and S         (ring-forming atom counts including atoms designated as Z¹ and         Z²); wherein the C₅₋₈ cycloalkyl and the 5- to 8-membered         heterocycle are independently optionally substituted with 1, 2,         3, 4 or 5 substituents independently selected from R¹⁰; and         wherein two substituents of the C₅₋₈ cycloalkyl or the 5- to         8-membered heterocycle, where present, optionally taken together         form a spiro, fused or bridged cycloalkyl (e.g., C₃₋₆         cycloalkyl) optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹⁰ or a sprio, fused         or bridged heterocyclyl (e.g., 3- to 6-membered heterocyclyl)         optionally substituted with 1, 2, 3 or 4 substituents         independently selected from R¹⁰;     -   R²⁰, R²¹, R²² and R²³ are each independently hydrogen or R¹⁰.

R³ is hydrogen, halogen, cyano, C₁₋₆ alkyl, C_(3-s) cycloalkyl, 3- to 14-membered heterocyclyl, or —OR⁷; wherein the C₁₋₆ alkyl, C_(3-s) cycloalkyl and 3- to 14-membered heterocyclyl of R³ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

R⁴ is C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl, 3- to 14-membered heterocyclyl, halogen, cyano, —C(O)R⁶, —C(O)OR⁷, —C(O)NR^(8a)R^(8b), —OR⁷, —OC(O)R⁶, —OC(O)NR^(8a)R^(8b), —SR⁷, —S(O)R⁹, —S(O)₂R⁹, —S(O)₂NR^(8a)R^(8b), —P(O)R^(9a)R^(9b), —NR^(8a)R^(8b), —N(R⁸)C(O)R⁶, —N(R⁸)C(O)OR⁷, —N(R⁸)C(O)NR^(8a)R^(8b), —N(R⁸)S(O)₂R⁹, or —N(R⁸)S(O)₂NR^(8a)R^(8b); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R⁴ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

each R⁶ is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁶ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

each R⁷ is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁷ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

each R⁸ is independently hydrogen or C₁₋₆ alkyl;

each R^(8a) and R^(8b) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(8a) and R^(8b) are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

-   -   or R^(8a) and R^(8b) are taken together with the nitrogen atom         to which they are attached to form a 4- to 12-membered         heterocyclyl optionally substituted with 1, 2, 3, 4 or 5         substituents independently selected from R¹⁰;

each R⁹ is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁹ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

each R^(9a) and R^(9b) is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl, 3- to 12-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(9a) and R^(9b) are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

-   -   or R^(9a) and R^(9b) are taken together with the phosphorus atom         to which they are attached to form a 4- to 12-membered         heterocyclyl optionally substituted with 1, 2, 3, 4 or 5         substituents independently selected from R¹⁰;

each R¹⁰ is independently oxo, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₉ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 12-membered heterocyclyl, halogen, cyano, —C(O)R^(a), —C(O)OR^(b), —C(O)NR^(c)R^(d), —OR^(b), —OC(O)R^(a), —OC(O)NR^(c)R^(d), —SR^(b), —S(O)R^(e), —S(O)₂R^(e), —S(O)(═NH)R^(e), —S(O)₂NR^(c)R^(d), —NR^(c)R^(d), —N(R¹)C(O)R^(a), —N(R¹)C(O)OR^(b), —N(R¹)C(O)NR^(c)R^(d), —N(R^(f2))S(O)₂R^(e), —N(R^(f2))S(O)₂NR^(c)R^(d), or —P(O)R^(g)R^(h); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R¹⁰ are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R^(a) is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(a) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R^(b) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(b) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R^(c) and R^(d) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(c) and R^(d) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

-   -   or R^(c) and R^(d) are taken together with the nitrogen atom to         which they are attached to form a 4- to 12-membered heterocyclyl         optionally substituted with 1, 2, 3 or 4 substituents         independently selected from R¹¹;

each R^(e) is independently C₁₋₆ alkyl, C₃₋₉ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(e) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R^(f) is independently hydrogen or C₁₋₆ alkyl;

each R^(g) and R^(h) is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 12-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(g) and R^(h) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

-   -   or R^(g) and R^(h) are taken together with the phosphorus atom         to which they are attached to form a 4- to 12-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹¹;

each R¹¹ is independently oxo, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 8-membered heterocyclyl, halogen, cyano, —C(O)R^(a1), —C(O)OR^(b1), —C(O)NR^(c1)R^(d1), —OR^(b1), —OC(O)R^(a1), —OC(O)NR^(c1)R^(d1), —SR^(b1), —S(O)R^(e1), —S(O)₂R^(e1), —S(O)₂NR^(c1)R^(d1), —NR^(c1)R^(d1), —N(R^(f1))C(O)R^(a1), —N(R^(f1))C(O)OR^(b1), —N(R^(f1))C(O)NR^(c1)R^(d1), —N(R^(f1))S(O)₂R^(e1), —N(R^(f1))S(O)₂NR^(c1)R^(a1), or —P(O)R^(g1)R^(h1); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R¹¹ are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R^(a1) is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(a1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R^(b1) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(b1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R^(c1) and R^(d1) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(c1) and R^(d1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

-   -   or R^(c1) and R^(d1) are taken together with the nitrogen atom         to which they are attached to form a 4- to 8-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹²;

each R^(e1) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(e1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R¹ is independently hydrogen or C₁₋₆ alkyl;

each R^(g1) and R^(h1) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 8-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(g1) and R^(h1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

-   -   or R^(g1) and R^(h1) are taken together with the phosphorus atom         to which they are attached to form a 4- to 8-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹²;

each R¹² is independently oxo, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl, 3- to 6-membered heterocyclyl, halogen, cyano, —C(O)R^(a2), —C(O)OR^(b2), —C(O)NR^(c2)R^(d2), —OR^(b)2, —OC(O)R^(a2), —OC(O)NR^(c2)R^(d2), —S(O)₂R^(e2), —S(O)₂NR^(c2)R^(d2), —NR^(c2)R^(d2), —N(R^(f2))C(O)R^(a2), —N(R^(f2))C(O)OR^(b2), —N(R^(f2))C(O)NR^(c2)R^(d2), —N(R^(f2))S(O)₂R^(e2), —N(R^(f2))S(O)₂NR^(c2)R^(d2), or —P(O)R^(g2)R^(h2); wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R¹² are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R^(a2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R^(a2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R^(b2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl and 3- to 6-membered heterocyclyl of R^(b2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R^(c2) and R^(d2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl and 3- to 8-membered heterocyclyl of R^(c2) and R^(d2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

-   -   or R^(c2) and R^(d2) are taken together with the nitrogen atom         to which they are attached to form a 4- to 6-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹³;

each R^(e2) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R^(e2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R^(f2) is independently hydrogen or C₁₋₆ alkyl;

each R^(g2) and R² is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, 3- to 8-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, and 3- to 8-membered heterocyclyl of R^(g2) and R² are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

-   -   or R^(g2) and R^(h) are taken together with the phosphorus atom         to which they are attached to form a 4- to 6-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹³; and

each R¹³ is independently oxo, halogen, hydroxyl, —O(C₁₋₆ alkyl), cyano, C₁₋₆ alkyl or C₁₋₆ haloalkyl.

In one aspect, provided is a compound of Formula (IA):

or a salt (e.g., a pharmaceutically acceptable salt) thereof, wherein:

R¹ is hydrogen, halogen, hydroxyl, C₁₋₆ alkyl optionally substituted with halogen, C₃₋₄ cycloalkyl, or —O(C₁₋₆ alkyl) optionally substituted with halogen;

Q is CR²⁰, NR²¹, N, O or S;

T is N or CR²²;

Z¹ and Z² are independently N or C, provided at least one of Z and Z² is C;

ring A is a C₅₋₈ cycloalkyl or a 5- to 8-membered heterocycle having at least 3 ring-forming carbon atoms and 1, 2 or 3 ring-forming heteroatoms independently selected from the group consisting of N, P, O and S; wherein the C₅₋₈ cycloalkyl and the 5- to 8-membered heterocycle are independently optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰; and wherein two substituents of the C₅₋₈ cycloalkyl or the 5- to 8-membered heterocycle, where present, optionally taken together form a spiro, fused or bridged cycloalkyl (e.g., C₃₋₆ cycloalkyl) optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰ or a sprio, fused or bridged heterocyclyl (e.g., 3- to 6-membered heterocyclyl) optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰;

R²⁰, R²¹ and R²² are each independently hydrogen or R^(IO).

R³ is hydrogen, halogen, cyano, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, 3- to 14-membered heterocyclyl, or —OR⁷; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl and 3- to 14-membered heterocyclyl of R³ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

R⁴ is C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₉ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl, 3- to 14-membered heterocyclyl, halogen, cyano, —C(O)R⁶, —C(O)OR⁷, —C(O)NR^(8a)R^(8b), —OR⁷, —OC(O)R⁶, —OC(O)NR^(8a)R^(8b), —SR⁷, —S(O)R⁹, —S(O)₂R⁹, —S(O)₂NR^(8a)R^(8b), —P(O)R^(9a)R^(9b), —NR^(8a)R^(8b), —N(R⁸)C(O)R⁶, —N(RI)C(O)OR⁷, —N(R⁸)C(O)NR^(8a)R^(8b), —N(R⁸)S(O)₂R⁹, or —N(R⁸)S(O)₂NR^(8a)R^(8b); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R⁴ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

each R⁶ is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁶ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

each R⁷ is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁷ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

each R⁸ is independently hydrogen or C₁₋₆ alkyl;

each R^(8a) and R^(8b) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(8a) and R^(8b) are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

-   -   or R^(8a) and R^(8b) are taken together with the nitrogen atom         to which they are attached to form a 4- to 12-membered         heterocyclyl optionally substituted with 1, 2, 3, 4 or 5         substituents independently selected from R¹⁰;

each R⁹ is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁹ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

each R^(9a) and R^(9b) is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl, 3- to 12-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(9a) and R^(9b) are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

-   -   or R^(9a) and R^(9b) are taken together with the phosphorus atom         to which they are attached to form a 4- to 12-membered         heterocyclyl optionally substituted with 1, 2, 3, 4 or 5         substituents independently selected from R¹⁰;

each R¹⁰ is independently oxo, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 12-membered heterocyclyl, halogen, cyano, —C(O)R^(a), —C(O)OR^(b), —C(O)NR^(c)R^(d), —OR^(b), —OC(O)R^(a), —OC(O)NR^(c)R^(d), —SR^(b), —S(O)R^(e), —S(O)₂R^(e), —S(O)(═NH)R^(e), —S(O)₂NR^(c)R^(d), —NR^(c)R^(d), —N(R^(f2))C(O)R^(a), —N(R^(f2))C(O)OR^(b), —N(R^(f2))C(O)NR^(c)R^(d), —N(R^(f2))S(O)₂R^(e), —N(R^(f2))S(O)₂NR^(c)R^(d), or —P(O)R^(g)R^(h); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R¹⁰ are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R^(a) is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(a) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R^(b) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(b) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R^(C) and R^(d) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(C) and R^(d) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

-   -   or R^(C) and R^(d) are taken together with the nitrogen atom to         which they are attached to form a 4- to 12-membered heterocyclyl         optionally substituted with 1, 2, 3 or 4 substituents         independently selected from R¹¹;

each R^(e) is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(e) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R^(f) is independently hydrogen or C₁₋₆ alkyl;

each R^(g) and R^(h) is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 12-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(g) and R^(h) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

-   -   or R^(g) and R^(h) are taken together with the phosphorus atom         to which they are attached to form a 4- to 12-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹¹;

each R¹¹ is independently oxo, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 8-membered heterocyclyl, halogen, cyano, —C(O)R^(a1), —C(O)OR^(b1), —C(O)NR^(c1)R^(d)1, —OR^(b1), —OC(O)R^(a1), —OC(O)NR^(c1)R^(d1), —SR^(b1), —S(O)R^(e1), —S(O)₂R^(e1), —S(O)₂NR^(c1)R^(d1), —NR^(c1)R^(d1), —N(R^(f1))C(O)R^(a1), —N(R^(f1))C(O)OR^(b1), —N(R^(f1))C(O)NR^(c1)R^(d1), —N(R^(f1))S(O)₂R^(e1), —N(R^(f1))S(O)₂NR^(c1)R^(d1), or —P(O)R^(g1)R^(h1); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R¹¹ are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R^(a1) is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(a1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R^(b1) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(b1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R^(c1) and R^(d1) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(c1) and R^(d1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹².

-   -   or R^(c1) and R^(d1) are taken together with the nitrogen atom         to which they are attached to form a 4- to 8-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹²;

each R^(e1) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(e1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R¹ is independently hydrogen or C₁₋₆ alkyl;

each R^(g1) and R^(h1) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 8-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(g1) and R^(h1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

-   -   or R^(g1) and R^(h1) are taken together with the phosphorus atom         to which they are attached to form a 4- to 8-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹²;

each R¹² is independently oxo, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl, 3- to 6-membered heterocyclyl, halogen, cyano, —C(O)R^(a2), —C(O)OR^(b2), —C(O)NR^(c2)R^(d2), —OR^(b)2, —OC(O)R^(a2), —OC(O)NR^(c2)R^(d2), —S(O)₂R^(e2), —S(O)₂NR^(c2)R^(d2), —NR^(c2)R^(d2), —N(R^(f2))C(O)R^(a2), —N(R^(f2))C(O)OR^(b2), —N(R^(f2))C(O)NR^(c2)R^(d2), —N(R^(f2))S(O)₂R^(e2), —N(R^(f2))S(O)₂NR^(c2)R^(d2), or —P(O)R^(g2)R^(h2); wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R¹² are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R^(a2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R^(a2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R^(b2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl and 3- to 6-membered heterocyclyl of R^(b2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R^(c2) and R^(d2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl and 3- to 8-membered heterocyclyl of R^(c2) and R^(d2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

-   -   or R^(c2) and R^(d2) are taken together with the nitrogen atom         to which they are attached to form a 4- to 6-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹³;

each R^(e2) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R^(e2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R^(h2) is independently hydrogen or C₁₋₆ alkyl;

each R^(g2) and R² is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, 3- to 8-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, and 3- to 8-membered heterocyclyl of R^(g2) and R² are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

-   -   or R^(g2) and R² are taken together with the phosphorus atom to         which they are attached to form a 4- to 6-membered heterocyclyl         optionally substituted with 1, 2, 3 or 4 substituents         independently selected from R¹³; and

each R¹³ is independently oxo, halogen, hydroxyl, —O(C₁₋₆ alkyl), cyano, C₁₋₆ alkyl or C₁₋₆ haloalkyl.

In one aspect, provided is a compound of Formula (IB):

or a salt (e.g., a pharmaceutically acceptable salt) thereof, wherein:

R¹ is hydrogen, halogen, hydroxyl, C₁₋₆ alkyl optionally substituted with halogen, C₃₋₄ cycloalkyl, or —O(C₁₋₆ alkyl) optionally substituted with halogen;

T¹, T² and T³ are independently N or CR²³;

ring B is a C₅₋₈ cycloalkyl or a 5- to 8-membered heterocycle having at least 3 ring-forming carbon atoms and 1, 2 or 3 ring-forming heteroatoms independently selected from the group consisting of N, P, O and S; wherein the C₅₋₈ cycloalkyl and the 5- to 8-membered heterocycle are independently optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰; and wherein two substituents of the C₅₋₈ cycloalkyl or the 5- to 8-membered heterocycle, where present, optionally taken together form a spiro, fused or bridged cycloalkyl (e.g., C₃₋₆ cycloalkyl) optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰ or a sprio, fused or bridged heterocyclyl (e.g., 3- to 6-membered heterocyclyl) optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰;

R²³ is hydrogen or R¹⁰.

R³ is hydrogen, halogen, cyano, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, 3- to 14-membered heterocyclyl, or —OR⁷; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl and 3- to 14-membered heterocyclyl of R³ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

R⁴ is C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl, 3- to 14-membered heterocyclyl, halogen, cyano, —C(O)R⁶, —C(O)OR⁷, —C(O)NR^(8a)R^(8b), —OR⁷, —OC(O)R⁶, —OC(O)NR^(8a)R^(8b), —SR⁷, —S(O)R⁹, —S(O)₂R⁹, —S(O)₂NR^(8a)R^(8b), —P(O)R^(9a)R^(9b), —NR^(8a)R^(8b), —N(R⁸)C(O)R⁶, —N(RI)C(O)OR⁷, —N(R⁸)C(O)NR^(8a)R^(8b), —N(R⁸)S(O)₂R⁹, or —N(R⁸)S(O)₂NR^(8a)R^(8b); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R⁴ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

each R⁶ is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁶ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

each R⁷ is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁷ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

each R⁸ is independently hydrogen or C₁₋₆ alkyl;

each R^(8a) and R^(8b) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(8a) and R^(8b) are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

-   -   or R^(8a) and R^(8b) are taken together with the nitrogen atom         to which they are attached to form a 4- to 12-membered         heterocyclyl optionally substituted with 1, 2, 3, 4 or 5         substituents independently selected from R¹⁰;

each R⁹ is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁹ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

each R^(9a) and R^(9b) is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl, 3- to 12-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(9a) and R^(9b) are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

-   -   or R^(9a) and R^(9b) are taken together with the phosphorus atom         to which they are attached to form a 4- to 12-membered         heterocyclyl optionally substituted with 1, 2, 3, 4 or 5         substituents independently selected from R¹⁰;

each R¹ is independently oxo, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 12-membered heterocyclyl, halogen, cyano, —C(O)R^(a), —C(O)OR^(b), —C(O)NR^(c)R^(d), —OR^(b), —OC(O)R^(a), —OC(O)NR^(c)R^(d), —SR^(b), —S(O)R^(c), —S(O)₂R^(e), —S(O)(═NH)R^(e), —S(O)₂NR^(c)R^(d), —NR^(c)R^(d), —N(R^(f2))C(O)R^(a), —N(R^(f2))C(O)OR^(b), —N(R^(f2))C(O)NR^(c)R^(d), —N(R^(f2))S(O)₂R^(e), —N(R^(f2))S(O)₂NR^(c)R^(d), or —P(O)R^(g)R^(h); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R¹ are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R^(a) is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(a) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R^(b) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(b) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R^(c) and R^(d) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(c) and R^(d) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

-   -   or R^(c) and R^(d) are taken together with the nitrogen atom to         which they are attached to form a 4- to 12-membered heterocyclyl         optionally substituted with 1, 2, 3 or 4 substituents         independently selected from R¹¹;

each R^(e) is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(e) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R^(f) is independently hydrogen or C₁₋₆ alkyl;

each R^(g) and R^(h) is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 12-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(g) and R^(h) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

-   -   or R^(g) and R^(h) are taken together with the phosphorus atom         to which they are attached to form a 4- to 12-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹¹;

each R¹¹ is independently oxo, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 8-membered heterocyclyl, halogen, cyano, —C(O)R^(a1), —C(O)OR^(b1), —C(O)NR^(c1)R^(d)1, —OR^(b1), —OC(O)R^(a1), —OC(O)NR^(c1)R^(d)1, —SR^(b1), —S(O)R^(e1), —S(O)₂R^(e1), —S(O)₂NR^(c1)R^(d)1, —NR^(c1)R^(d1), —N(R^(f1))C(O)R^(a1), —N(R^(f1))C(O)OR^(b1), —N(R^(f1))C(O)NR^(c1)R^(d1), —N(R^(f1))S(O)₂R^(e1), —N(R^(f1))S(O)₂NR^(c1)R^(d1), or —P(O)R^(g1)R^(h1); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R¹¹ are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R^(a1) is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(a1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R^(b1) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(b1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R^(c1) and R^(d1) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(c1) and R^(d1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹².

-   -   or R^(c1) and R^(d1) are taken together with the nitrogen atom         to which they are attached to form a 4- to 8-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹²;

each R^(e1) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆-10 aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(e) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R^(f1) is independently hydrogen or C₁₋₆ alkyl;

each R^(g1) and R^(h1) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆-10 aryl, 5- to 10-membered heteroaryl, 3- to 8-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(g1) and R^(h1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

-   -   or R^(g1) and R^(h1) are taken together with the phosphorus atom         to which they are attached to form a 4- to 8-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹²;

each R¹² is independently oxo, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl, 3- to 6-membered heterocyclyl, halogen, cyano, —C(O)R^(a2), —C(O)OR^(b2), —C(O)NR^(c2)R^(d2), —OR^(b2), —OC(O)R^(a2), —OC(O)NR^(c2)R^(d2), —S(O)₂R^(e2), —S(O)₂NR^(c2)R^(d2), —NR^(c2)R^(d2), —N(R^(f2))C(O)R^(a2), —N(R^(f2))C(O)OR^(b2), —N(R^(f2))C(O)NR^(c2)R^(d2), —N(R^(f2))S(O)₂R^(e2), —N(R^(f2))S(O)₂NR^(c2)R^(d2), or —P(O)R^(g2)R^(h2); wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R¹² are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R^(a2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R^(a2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R^(b2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl and 3- to 6-membered heterocyclyl of R^(b2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R^(c2) and R^(d2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl and 3- to 8-membered heterocyclyl of R^(c2) and R^(d2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

-   -   or R^(c2) and R^(d2) are taken together with the nitrogen atom         to which they are attached to form a 4- to 6-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹³;

each R^(e2) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R^(e2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R^(f2) is independently hydrogen or C₁₋₆ alkyl;

each R^(g2) and R^(h) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, 3- to 8-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, and 3- to 8-membered heterocyclyl of R^(g2) and R^(k) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

-   -   or R^(g2) and R^(h) are taken together with the phosphorus atom         to which they are attached to form a 4- to 6-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹³; and

each R¹³ is independently oxo, halogen, hydroxyl, —O(C₁₋₆ alkyl), cyano, C₁₋₆ alkyl or C₁₋₆ haloalkyl.

In one aspect, provided is a compound of Formula (IC):

or a salt (e.g., a pharmaceutically acceptable salt) thereof, wherein:

R¹ is hydrogen, halogen, hydroxyl, C₁₋₆ alkyl optionally substituted with halogen, C₃₋₄ cycloalkyl, or —O(C₁₋₆ alkyl) optionally substituted with halogen;

R² is a monocyclic 5- or 6-membered heteroaryl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰;

R³ is hydrogen, halogen, cyano, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, 3- to 14-membered heterocyclyl, or —OR⁷; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl and 3- to 14-membered heterocyclyl of R³ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

R⁴ is C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl, 3- to 14-membered heterocyclyl, halogen, cyano, —C(O)R⁶, —C(O)OR⁷, —C(O)NR^(8a)R^(8b), —OR⁷, —OC(O)R⁶, —OC(O)NR^(8a)R^(8b), —SR⁷, —S(O)R⁹, —S(O)₂R⁹, —S(O)₂NR^(8a)R^(8b), —P(O)R^(9a)R^(9b), —NR^(8a)R^(8b), —N(R⁸)C(O)R⁶, —N(RI)C(O)OR⁷, —N(R⁸)C(O)NR^(8a)R^(8b), —N(R⁸)S(O)₂R⁹, or —N(R⁸)S(O)₂NR^(8a)R^(8b); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R⁴ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

each R⁶ is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁶ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

each R⁷ is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁷ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

each R⁸ is independently hydrogen or C₁₋₆ alkyl;

each R^(8a) and R^(8b) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(8a) and R^(8b) are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

-   -   or R^(8a) and R^(8b) are taken together with the nitrogen atom         to which they are attached to form a 4- to 12-membered         heterocyclyl optionally substituted with 1, 2, 3, 4 or 5         substituents independently selected from R¹⁰;

each R⁹ is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁹ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

each R^(9a) and R^(9b) is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl, 3- to 12-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(9a) and R^(9b) are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰;

-   -   or R^(9a) and R^(9b) are taken together with the phosphorus atom         to which they are attached to form a 4- to 12-membered         heterocyclyl optionally substituted with 1, 2, 3, 4 or 5         substituents independently selected from R¹⁰;

each R¹ is independently oxo, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 12-membered heterocyclyl, halogen, cyano, —C(O)R^(a), —C(O)OR^(b), —C(O)NR^(c)R^(d), —OR^(b), —OC(O)R^(a), —OC(O)NR^(c)R^(d), —SR^(b), —S(O)R^(c), —S(O)₂R^(e), —S(O)(═NH)R^(e), —S(O)₂NR^(c)R^(d), —NR^(c)R^(d), —N(R^(f2))C(O)R^(a), —N(R^(f2))C(O)OR^(b), —N(R^(f2))C(O)NR^(c)R^(d), —N(R^(f2))S(O)₂R^(e), —N(R^(f2))S(O)₂NR^(c)R^(d), or —P(O)R^(g)R^(h); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R¹ are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R^(a) is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(a) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R^(b) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(b) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R^(c) and R^(d) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(c) and R^(d) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

-   -   or R^(c) and R^(d) are taken together with the nitrogen atom to         which they are attached to form a 4- to 12-membered heterocyclyl         optionally substituted with 1, 2, 3 or 4 substituents         independently selected from R¹¹;

each R^(e) is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(e) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

each R is independently hydrogen or C₁₋₆ alkyl;

each R^(g) and R^(h) is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 12-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(g) and R^(h) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹;

-   -   or R^(g) and R^(h) are taken together with the phosphorus atom         to which they are attached to form a 4- to 12-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹¹;

each R¹¹ is independently oxo, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 8-membered heterocyclyl, halogen, cyano, —C(O)R^(a1), —C(O)OR^(b1), —C(O)NR^(c1)R^(d)1, —OR^(b1), —OC(O)R^(a1), —OC(O)NR^(c1)R^(d)1, —SR^(b1), —S(O)R^(e1), —S(O)₂R^(e1), —S(O)₂NR^(c1)R^(d)1, —NR^(c1)R^(d1), —N(R^(f1))C(O)R^(a1), —N(R^(f1))C(O)OR^(b1), —N(R^(f1))C(O)NR^(c1)R^(d1), —N(R^(f1))S(O)₂R^(e1), —N(R^(f1))S(O)₂NR^(c1)R^(d1), or —P(O)R^(g1)R^(h1); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R¹¹ are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R^(a1) is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(a1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R^(b1) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(b1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R^(c1) and R^(d1) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(c1) and R^(d1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹².

-   -   or R^(c1) and R^(d1) are taken together with the nitrogen atom         to which they are attached to form a 4- to 8-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹²;

each R^(e1) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆-10 aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(e) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

each R^(f1) is independently hydrogen or C₁₋₆ alkyl;

each R^(g1) and R^(h1) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆-10 aryl, 5- to 10-membered heteroaryl, 3- to 8-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(g1) and R^(h1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²;

-   -   or R^(g1) and R^(h1) are taken together with the phosphorus atom         to which they are attached to form a 4- to 8-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹²;

each R¹² is independently oxo, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl, 3- to 6-membered heterocyclyl, halogen, cyano, —C(O)R^(a2), —C(O)OR^(b2), —C(O)NR^(c2)R^(d2), —OR^(b2), —OC(O)R^(a2), —OC(O)NR^(c2)R^(d2), —S(O)₂R^(e2), —S(O)₂NR^(c2)R^(d2), —NR^(c2)R^(d2), —N(R^(f2))C(O)R^(a2), —N(R^(f2))C(O)OR^(b2), —N(R^(f2))C(O)NR^(c2)R^(d2), —N(R^(f2))S(O)₂R^(e2), —N(R^(f2))S(O)₂NR^(c2)R^(d2), or —P(O)R^(g2)R^(h2); wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R¹² are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R^(a2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R^(a2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R^(b2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl and 3- to 6-membered heterocyclyl of R^(b2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R^(c2) and R^(d2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl and 3- to 8-membered heterocyclyl of R^(c2) and R^(d2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

-   -   or R^(c2) and R^(d2) are taken together with the nitrogen atom         to which they are attached to form a 4- to 6-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹³;

each R^(e2) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R^(e2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

each R¹ is independently hydrogen or C₁₋₆ alkyl;

each R^(g2) and R^(k) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, 3- to 8-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, and 3- to 8-membered heterocyclyl of R^(g2) and R^(h) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³;

-   -   or R^(g2) and R^(h2) are taken together with the phosphorus atom         to which they are attached to form a 4- to 6-membered         heterocyclyl optionally substituted with 1, 2, 3 or 4         substituents independently selected from R¹³; and

each R¹³ is independently oxo, halogen, hydroxyl, —O(C₁₋₆ alkyl), cyano, C₁₋₆ alkyl or C₁₋₆ haloalkyl.

In some embodiments, the compound is of the Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a salt (e.g., a pharmaceutically acceptable salt) thereof, wherein R¹ is hydrogen, halogen, hydroxyl, C₁₋₆ alkyl optionally substituted with halogen, C₃₋₄ cycloalkyl, or —O(C₁₋₆ alkyl) optionally substituted with halogen. In some embodiments, R¹ is hydrogen, hydroxy, —O(C₁₋₆ alkyl), or C₁₋₆ alkyl optionally substituted with cyano. In some embodiments, R¹ is hydrogen, C₃₋₄ cycloalkyl, C₁₋₆ alkyl, C₁₋₆ haloalkyl, —O(C₁₋₆ alkyl) or —O(C₁₋₆ haloalkyl). In one variation, R¹ is hydrogen or C₁₋₆ alkyl (e.g., methyl). In another variation, R¹ is methyl, hydroxyl, methoxy or cyanomethyl. In another variation, R¹ is hydrogen.

In some embodiments, the compound is of the Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a salt (e.g., a pharmaceutically acceptable salt) thereof, wherein R³ is hydrogen, halogen, cyano, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, 3- to 14-membered heterocyclyl, or —OR⁷; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl and 3- to 14-membered heterocyclyl of R³ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰. In some embodiments, R³ is hydrogen, fluoro, chloro, cyano, hydroxyl, C₃₋₄ cycloalkyl, C₁₋₆ alkyl, C₁₋₆ haloalkyl, —O(C₁₋₆ alkyl) or —O(C₁₋₆ haloalkyl). In one variation, R³ is hydrogen, fluoro, cyano, or C₁₋₆ alkyl (e.g., methyl). In another variation, R³ is hydrogen or halogen. In another variation, R³ is hydrogen or fluoro. In another variation, R³ is hydrogen.

It is intended and understood that each and every variation of R¹ and R³ described for the Formula (I), (IA), (IB) or (IC) may be combined, the same as if each and every combination is specifically and individually described. For example, in some embodiments, R¹ is hydrogen, or C₁₋₆ alkyl (e.g., methyl) and R³ is hydrogen or fluoro. In one variation, R¹ is hydrogen or methyl and R³ is hydrogen.

In some embodiments, the compound is of the Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a salt (e.g., a pharmaceutically acceptable salt) thereof, wherein R⁴ is C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₉ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl, 3- to 14-membered heterocyclyl, halogen, cyano, —C(O)R⁶, —C(O)OR⁷, —C(O)NR^(8a)R^(8b), —OR⁷, —OC(O)R⁶, —OC(O)NR^(8a)R^(8b), —SR⁷, —S(O)R⁹, —S(O)₂R⁹, —S(O)₂NR^(8a)R^(8b), —P(O)R^(9a)R^(9b), —NR^(8a)R^(8b), —N(R⁸)C(O)R⁶, —N(R⁸)C(O)OR⁷, —N(R⁸)C(O)NR^(8a)R^(8b), —N(R⁸)S(O)₂R⁹, or —N(R⁸)S(O)₂NR^(8a)R^(8b); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R⁴ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰.

In some embodiments, R⁴ is C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₉ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl, 3- to 14-membered heterocyclyl, halogen, cyano, —C(O)R⁶, —C(O)OR⁷, —OC(O)R⁶, —OC(O)NR^(8a)R^(8b), —SR⁷, —S(O)R⁹, —S(O)₂R⁹, —S(O)₂NR^(8a)R^(8b), —P(O)R^(9a)R^(9b), —NR^(8a)R^(8b), —N(R⁸)C(O)R⁶, —N(RI)C(O)OR⁷, —N(R⁸)C(O)NR^(8a)R^(8b), —N(R⁸)S(O)₂R⁹, or —N(R⁸)S(O)₂NR^(8a)R^(8b); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R⁴ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰.

In some embodiments, R⁴ is C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₉ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl, 3- to 14-membered heterocyclyl, cyano, —C(O)R⁶, —OC(O)R⁶, —OC(O)NR^(8a)R^(8b), —SR⁷, —S(O)R⁹, —S(O)₂R⁹, —S(O)₂NR^(8a)R^(8b), —P(O)R^(9a)R^(9b), —NR^(8a)R^(8b), —N(R⁸)C(O)R⁶, —N(R⁸)C(O)OR⁷, —N(R⁸)C(O)NR^(8a)R^(8b), —N(R⁸)S(O)₂R⁹, or —N(R⁸)S(O)₂NR^(8a)R^(8b); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R⁴ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰.

In some embodiments, R⁴ is

In some embodiments, R⁴ is C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl or 3- to 14-membered heterocyclyl; wherein the C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R⁴ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰.

In some embodiments, R⁴ is

In some embodiments, R⁴ is C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 5- to 6-membered heterocyclyl; wherein the C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 5- to 6-membered heterocyclyl of R⁴ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰.

In some embodiments, R⁴ is

wherein the wavy line represents the attachment point to the parent structure, R^(4a), R^(4b) and R^(4c) are each independently hydrogen or R¹⁰, or two vicinal R^(4(a-c)) are taken together with the atoms to which they are attached form a fused 5- or 6-membered heteroaryl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰ or a fused 5- or 6-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰.

In one variation, R⁴ is or R

In one variation, R⁴ is 5- to 10-membered heteroaryl optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰.

In some embodiments, R⁴ is

In one variation, R⁴ is

In another variation, R⁴ is selected from the group consisting of:

each of which can be optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰.

It is intended and understood that each and every variation of R¹ and R³, or a combination thereof, described for the Formula (I), (IA), (IB) or (IC) may be combined with each and every variation of R⁴ described for the Formula (I), (IA), (IB) or (IC), the same as if each and every combination is specifically and individually described. For example, in some embodiments, R¹ is hydrogen or C₁₋₆ alkyl (e.g., methyl); R³ is hydrogen or fluoro; and R⁴ is C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 5- to 6-membered heterocyclyl; wherein the C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 5- to 6-membered heterocyclyl of R⁴ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰. In one variation, R¹ is hydrogen or methyl; R³ is hydrogen; and R⁴ is

In some embodiments, the compound is of the Formula (I), or variations thereof such as Formula (IA), (IB) and (IC) where applicable, or a salt (e.g., a pharmaceutically acceptable salt) thereof, wherein R² is a 5- to 14-membered heteroaryl optionally substituted with R¹⁰. In some embodiments, R² is a monocyclic 5- or 6-membered heteroaryl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰. In some embodiments, R² is a polycyclic heteroaryl having the formula (a) or (b):

wherein the wavy line represents the attachment point to the parent structure.

In some embodiments, the compound is of the Formula (I), or a salt (e.g., a pharmaceutically acceptable salt) thereof, wherein R² is a polycyclic heteroaryl having the formula (a):

or the compound is of the Formula (IA):

or a salt (e.g., a pharmaceutically acceptable salt) thereof, wherein Q, T, Z¹, Z² and ring A are as described herein.

In some embodiments, Q is CR²⁰, NR²¹, N, O or S; T is N or CR²²; Z¹ and Z² are independently N or C, provided at least one of Z¹ and Z² is C; ring A is a 5- to 8-membered heterocycle having at least 3 ring-forming carbon atoms and 1, 2 or 3 ring-forming heteroatoms independently selected from the group consisting of N, P, O and S, wherein the 5- to 8-membered heterocycle is optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰, and two germinal substituents of the 5- to 8-membered heterocycle, where present, optionally taken together with the atom to which they are attached form a spiro C₃₋₆ cycloalkyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹ or a sprio 3- to 6-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰, or two vicinal substituents of the 5- to 8-membered heterocycle, where present, optionally taken together with the atoms to which they are attached form a fused 5- or 6-membered heteroaryl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰ or a fused 5- or 6-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰; and R²⁰, R²¹ and R²² are each independently hydrogen or R¹⁰. In one variation, R²⁰, R²¹ and R²² are each independently hydrogen, halogen, hydroxyl, —O(C₁₋₆ alkyl), cyano, C₁₋₆ alkyl or C₁₋₆ haloalkyl.

In some embodiments, Q is CR²⁰. In some embodiments, Q is NR²¹, O or S. In some embodiments, Q is NR²¹. In some embodiments, Q is S. In some embodiments, T is N. In some embodiments, T is NR²². In some embodiments, Z¹ is N and Z² is C. In some embodiments, Z¹ is C and Z² is C. In some embodiments, Z¹ is C and Z² is N. In one variation, Q is CR²⁰; T is N; Z¹ is N and Z² is C. In some embodiments, Q is NR²¹; T is N; Z¹ is C and Z² is C. In some embodiments, Q is S; T is N; Z¹ is C and Z² is C. In one variation, R²⁰, R²¹ and R²² are each independently hydrogen, halogen, hydroxyl, —O(C₁₋₆ alkyl), cyano, C₁₋₆ alkyl (e.g., methyl), or C₁₋₆ haloalkyl (e.g., —CF₃). In one variation, R²⁰ is hydrogen or methyl. In one variation, R²⁰ is hydrogen. In one variation, R²¹ is hydrogen. In one variation, R²² is hydrogen.

In some of these embodiments, R² in the Formula (I) or the moiety of formula (a) in the Formula (IA) is:

wherein q is 0, 1, 2, 3, 4, 5 or 6; R²⁴ is independently hydrogen or R¹⁰; Y is C₁ alkylene wherein optionally one or more of the carbon atoms of the C₁ alkylene are replaced by a heteroatom selected from oxygen, sulfur and nitrogen, and the C₁ alkylene is optionally substituted with R¹⁰; and R¹⁰ and R²⁰ are as detailed herein. In some embodiments, two of the R¹⁰ substituents optionally taken together form a spiro, fused or bridged cycloalkyl (e.g., C₃₋₆ cycloalkyl) optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹ or a sprio, fused or bridged heterocyclyl (e.g., 3- to 6-membered heterocyclyl) optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹. In one variation, R²⁴ is independently hydrogen or C₁₋₆ alkyl; and R²⁰ is hydrogen. In one variation, R²⁴ is hydrogen. In one variation, Y is Cia alkylene optionally substituted with R¹⁰. In one variation, R² in the Formula (I) or the moiety of formula (a) in the Formula (IA) is:

In one such variation, R²⁴ is independently hydrogen or C₁₋₆ alkyl; and R²⁰ is hydrogen. In one such variation, R²⁴ is hydrogen.

In some embodiments, R² in the Formula (I) or the moiety of formula (a) in the Formula (IA) is:

In some of these embodiments, R² in the Formula (I) or the moiety of formula (a) in the Formula (IA) is:

wherein q is 0, 1, 2, 3 or 4; R²⁴ is independently hydrogen or R¹⁰; and R¹⁰ and R²⁰ are as detailed herein. In one variation, R²⁴ is independently hydrogen or C₁₋₆ alkyl; and R²⁰ is hydrogen. In one variation, R²⁴ is hydrogen. In one variation, R² in the Formula (I) or the moiety of formula (a) in the Formula (IA) is:

In one such variation, R²⁴ is independently hydrogen or C₁₋₆ alkyl; and R²⁰ is hydrogen. In one such variation, R²⁴ is hydrogen.

In some embodiments, R² in the Formula (I) or the moiety of formula (a) in the Formula (IA) is:

In some of these embodiments, R² in the Formula (I) or the moiety of formula (a) in the Formula (IA) is:

wherein p is 0, 1, 2, 3 or 4; R²⁴ is independently hydrogen or R¹⁰; and R¹⁰ and R²⁰ are as detailed herein. In one variation, R²⁴ is independently hydrogen or C₁₋₆ alkyl; and R²⁰ is hydrogen.

In some of these embodiments, R² in the Formula (I) or the moiety of formula (a) in the Formula (IA) is:

wherein p is 0, 1, 2, 3 or 4; R²⁴ is independently hydrogen or R¹⁰; and R¹⁰ and R²⁰ are as detailed herein. In one variation, R²⁴ is independently hydrogen or C₁₋₆ alkyl; and R²⁰ is hydrogen.

In some embodiments, R² in the Formula (I) or the moiety of formula (a) in the Formula (IA) is

In some of these embodiments, R² in the Formula (I) or the moiety of formula (a) in the Formula (IA) is:

wherein X is CH₂, N, O or S; n is 1, 2, 3 or 4; p is 0, 1, 2, 3 or 4; R²⁴ is hydrogen or R¹⁰; and R¹⁰ and R²⁰ are as detailed herein. In one variation, R²⁴ is independently hydrogen or C₁₋₆ alkyl; and R²⁰ is hydrogen.

In some of these embodiments, R² in the Formula (I) or the moiety of formula (a) in the Formula (IA) is:

wherein q is 0, 1, 2, 3, 4, 5 or 6; and R¹⁰ and R²⁰ are as detailed herein. In one variation, R²⁰ is hydrogen.

In some embodiments, R² in the Formula (I) or the moiety of formula (a) in the Formula (IA) is or

In some of these embodiments, R² in the Formula (I) or the moiety of formula (a) in the Formula (IA) is:

wherein Q is NR²¹, O or S;

X is CR^(26a)R^(26b), NR²⁴, O or S,

X′ is CR^(27a)R^(27b), NR²⁴, O, S or S(O)₂,

R²⁴, R^(25a), R^(25b), R^(26a) and R^(26b) are independently hydrogen or R¹⁰;

R^(27a) and R^(27b) are independently hydrogen or R¹⁰, or R^(27a) and R^(27b) are taken together with the carbon atom to which they are attached to form a C₃₋₈ cycloalkyl or 3- to 8-membered heterocyclyl; and

R¹⁰ and R²¹ are as detailed herein.

In one variation, R² in the Formula (I) or the moiety of formula (a) in the Formula (IA) is:

In one such variation, R²⁴, where present, is independently hydrogen or C₁₋₆ alkyl; and R²¹, where present, is hydrogen.

In some of these embodiments, R² in the Formula (I) or the moiety of formula (a) in the Formula (IA) is:

wherein q is 0, 1, 2, 3, 4, 5 or 6;

G is independently C or N;

G′ is independently N, NR²⁸, CR²⁹, S or O;

R²⁸ and R²⁹ are independently hydrogen or R¹¹; or two vicinal groups R²⁸ and R²⁹ are taken together to form a 5- to 6-membered heterocyclyl; and

R¹⁰, R¹¹ and R²⁰ are as detailed herein.

In one variation, R² in the Formula (I) or the moiety of formula (a) in the Formula (IA) is:

In one variation, R² in the Formula (I) or the moiety of formula (a) in the Formula (IA) is:

In one such variation, R²⁸ is independently hydrogen or C₁₋₆ alkyl; and R²⁰ is hydrogen.

In some embodiments, the compound is of the Formula (I), or a salt (e.g., a pharmaceutically acceptable salt) thereof, wherein R² is a polycyclic heteroaryl having the formula (b):

or the compound is of the Formula (IB):

or a salt (e.g., a pharmaceutically acceptable salt) thereof, wherein T¹, T², T³, and ring B are as described herein.

In some embodiments, T¹, T² and T³ are independently N or CR²³; ring B is a 5- to 8-membered heterocycle having at least 3 ring-forming carbon atoms and 1, 2 or 3 ring-forming heteroatoms independently selected from the group consisting of N, P, O and S, wherein the 5- to 8-membered heterocycle is optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰, and two germinal substituents of the 5- to 8-membered heterocycle, where present, optionally taken together with the atom to which they are attached form a spiro C₃₋₆ cycloalkyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰ or a sprio 3- to 6-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰, or two vicinal substituents of the 5- to 8-membered heterocycle, where present, optionally taken together with the atoms to which they are attached form a fused 5- or 6-membered heteroaryl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰ or a fused 5- or 6-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰; and R²³ is hydrogen or R¹⁰. In one variation, at least one of T¹, T² and T³ is N. In one variation, R²³ is hydrogen, halogen, hydroxyl, —O(C₁₋₆ alkyl), cyano, C₁₋₆ alkyl or C₁₋₆ haloalkyl.

In some embodiments, at least one of T¹, T² and T³ is N. In some embodiments, one of T¹, T² and T³ is N; and the remaining two of T¹, T² and T³ are independently CR²³. In some embodiments, T¹ is N, and T² and T³ are independently CR²³. In some embodiments, T² is N, and T¹ and T³ are independently CR²³. In some embodiments, T³ is N, and T¹ and T² are independently CR²³. In some embodiments, one of T¹, T² and T³ is CR²³; and the remaining two of T¹, T² and T³ are N. In some embodiments, T¹ and T² are N; and T³ is CR²³. In some embodiments, T¹ and T³ are N; and T² is CR²³. In one variation, R²³ is hydrogen, halogen, hydroxyl, —O(C₁₋₆ alkyl), cyano, C₁₋₆ alkyl (e.g., methyl), or C₁₋₆ haloalkyl (e.g., —CF₃). In one variation, R²³ is hydrogen or methyl. In one variation, R²³ is hydroxyl. In one variation, R²³ is hydrogen.

In some of these embodiments, R² in the Formula (I) or the moiety of formula (b) in the Formula (IB) is:

wherein q is 0, 1, 2, 3 or 4; and R¹⁰, R²³ and R²⁴ are as detailed herein. In one variation, each R²³ is hydrogen and R²⁴ is hydrogen or C₁₋₆ alkyl (e.g., methyl). In one variation, R² in the Formula (I) or the moiety of formula (b) in the Formula (IB) is:

In some embodiments, the compound is of the Formula (I) or (IC):

or a salt (e.g., a pharmaceutically acceptable salt) thereof, wherein R² is a monocyclic 5- or 6-membered heteroaryl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰.

In some of these embodiments, R² is a 5-membered heteroaryl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰. In some of these embodiments, R² is a 6-membered heteroaryl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰.

In some of these embodiments, R² is

wherein the wavy line represents the attachment point to the parent structure, and R^(2a), R^(2b), R^(2c) and R^(2d) are each independently hydrogen or R¹⁰. In one variation, R² is

In some embodiments, R^(2a), R^(2b), R^(2c) and R^(2d) (where present) are each independently hydrogen; C₁₋₆ alkyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹; C₃₋₈ cycloalkyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹; or 3- to 14-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹. In some embodiments, R^(2a), R^(2b), R^(2c) and R^(2d) (where present) are each independently hydrogen or C₁₋₆ alkyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from halogen and cyano [e.g., methyl, ethyl, difluoromethyl, or 1-cyanoethyl]. In some embodiments, R^(2a), R^(2b), R^(2c) and R^(2d) (where present) are each independently hydrogen or C₁₋₆ alkyl optionally substituted with 3- to 14-membered heterocyclyl with is optionally substituted with C₁₋₆ alkyl [e.g., (1-methylpyrrolidin-3-yl)methyl]. In some embodiments, R^(2a), R^(2b), R^(2c) and R^(2d) (where present) are each independently hydrogen or 3- to 14-membered heterocyclyl [e.g., tetrahydrofuran-3-yl] optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹.

In some embodiments, R² is

In some embodiments, R² is

In some embodiments of the compounds of the Formula (IC), R⁴ is C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl, 3- to 14-membered heterocyclyl, cyano, —C(O)R⁶, —OC(O)R⁶, —OC(O)NR^(8a)R^(8b), —SR⁷, —S(O)R⁹, —S(O)₂R⁹, —S(O)₂NR^(8a)R^(8b), —NR^(8a)R^(8b), —N(R⁸)C(O)R⁶, —N(R⁸)C(O)OR⁷, —N(R⁸)C(O)NR^(8a)R^(8b), —N(R⁸)S(O)₂R⁹, or —N(R⁸)S(O)₂NR^(8a)R^(8b); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R⁴ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰. In one variation, R⁴ is C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl or 3- to 14-membered heterocyclyl; wherein the C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R⁴ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰.

It is intended and understood that each and every variation of R¹, R³ and R⁴, or a combination thereof, described for the Formula (I), (IA), (IB) or (IC) may be combined with each and every variation of R² described for the Formula (I), or the Formula (IA), (IB) or (IC) where applicable, the same as if each and every combination is specifically and individually described. For example, in some embodiments, R¹ is hydrogen or C₁₋₆ alkyl (e.g., methyl); R³ is hydrogen or fluoro; R⁴ is C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 5- to 6-membered heterocyclyl; wherein the C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 5- to 6-membered heterocyclyl of R⁴ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰; and R² is of the formula (a) wherein Q is CR²⁰; T is N; Z¹ is N; Z² is C; and ring A is as detailed herein. In one variation, R¹ is hydrogen, fluoro, or methyl; R³ is hydrogen; R⁴ is

and R² is of the formula (a) wherein Q is CH; T is N; Z¹ is N and Z² is C.

In some embodiments of the compound of the Formula (I), or variations thereof such as Formula (IA), (IB) and (IC) where applicable, or a salt (e.g., a pharmaceutically acceptable salt) thereof, each R⁶ is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁶ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰. In one variation, R⁶ is C₁₋₆ alkyl, C₃₋₈ cycloalkyl, or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, and 3- to 12-membered heterocyclyl of R⁶ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰. In one variation, R⁶ is 3- to 12-membered heterocyclyl optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰ [e.g., 4-methylpiperazin-1-yl].

In some embodiments of the compound of the Formula (I), or variations thereof such as Formula (IA), (IB) and (IC) where applicable, or a salt (e.g., a pharmaceutically acceptable salt) thereof, each R⁷ is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁷ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰. In one variation, R⁷ is hydrogen, C₁₋₆ alkyl optionally substituted with R¹⁰. In one variation, R⁷ is 3- to 12-membered heterocyclyl [e.g., piperidin-4-yl].

In some embodiments of the compound of the Formula (I), or variations thereof such as Formula (IA), (IB) and (IC) where applicable, or a salt (e.g., a pharmaceutically acceptable salt) thereof, each R⁸ is independently hydrogen or C₁₋₆ alkyl; and each R^(8a) and R^(8b) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(8a) and R^(8b) are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰; or R^(8a) and R^(8b) are taken together with the nitrogen atom to which they are attached to form a 4- to 12-membered heterocyclyl optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰. In one variation, R⁸ is hydrogen or C₁₋₆ alkyl (e.g., methyl). In one variation, each R^(8a) and R^(8b) is independently hydrogen or C₁₋₆ alkyl. In one variation, R^(8a) and R^(8b) are taken together with the nitrogen atom to which they are attached to form a 5- to 7-membered heterocyclyl optionally substituted with R¹⁰.

In some embodiments of the compound of the Formula (I), or variations thereof such as Formula (IA), (IB) and (IC) where applicable, or a salt (e.g., a pharmaceutically acceptable salt) thereof, each R⁹ is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁹ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰. In one variation, R⁹ is C₁₋₆ alkyl optionally substituted with R¹⁰; or C₆₋₁₀ aryl optionally substituted with R¹⁰.

In some embodiments of the compound of the Formula (I), or variations thereof such as Formula (IA), (IB) and (IC) where applicable, or a salt (e.g., a pharmaceutically acceptable salt) thereof, each R¹⁰ is independently oxo, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 12-membered heterocyclyl, halogen, cyano, —C(O)R^(a), —C(O)OR^(b), —C(O)NR^(c)R^(d), —OR^(b), —OC(O)R^(a), —OC(O)NR^(c)R^(d), —SR^(b), —S(O)R^(e), —S(O)₂R^(e), —S(O)(═NH)R^(e), —S(O)₂NR^(c)R^(d), —NR^(c)R^(d), —N(R^(f2))C(O)R^(a), —N(R^(f2))C(O)OR^(b), —N(R^(f2))C(O)NR^(c)R^(d), —N(R^(f2))S(O)₂R^(e), or —N(R^(f2))S(O)₂NR^(c)R^(d); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R¹⁰ are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹.

In one variation, R¹⁰ is independently oxo; C₁₋₆ alkyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹; 5- to 10-membered heteroaryl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹; halogen, —OR^(b), —S(O)(═NH)R^(e), —NR^(c)R^(d), —N(R^(f2))C(O)R^(a), or —N(R^(f2))S(O)₂NR^(c)R^(d).

In one variation, R¹⁰ is independently oxo, halogen, cyano, C₁₋₆ alkyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹, or —OR^(b).

In one variation, R¹⁰ is independently —NR^(c)R^(d), —N(R^(f2))C(O)R^(a), —N(R^(f2))C(O)OR^(b), —N(R^(f2))C(O)NR^(c)R^(d), —N(R^(f2))S(O)₂R^(e), or —N(R^(f2))S(O)₂NR^(c)R^(d).

In one variation, R¹⁰ is independently oxo, —OR^(b), —OC(O)R^(a), —OC(O)NR^(c)R^(d), —SR^(b), —S(O)R^(e), —S(O)₂R^(e), —S(O)(═NH)R^(e), or —S(O)₂NR^(c)R^(d).

In one variation, each R¹⁰ is independently C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 12-membered heterocyclyl, halogen, cyano, —C(O)R^(a), —C(O)OR^(b), —C(O)NR^(c)R^(d); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R¹⁰ are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹.

In one variation, each R¹⁰ is independently C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹.

In one variation, R¹⁰ is C₁₋₆ alkyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹. In one variation, R¹⁰ is 3- to 12-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹.

In one variation, R¹⁰ is halogen, cyano, —NR^(c)R^(d), —C(O)NR^(c)R^(d), —OR^(b), —S(O)₂R^(e), C₁₋₆ haloalkyl, —(C₁₋₆ alkylene)-OH, or —(C₁₋₆ alkylene)-OH.

In one variation, R¹⁰ is hydroxyl, cyano, halogen, —CHF₂, —CF₃, —NH₂, —NH(C₁₋₆ alkyl), —N(C₁₋₆ alkyl)₂, —O(C₁₋₆ alkyl), —SO₂(C₁₋₆ alkyl), —S(O)₂NR^(c)R^(d), —C(O)NR^(c)R^(d), or —N(R^(f2))C(O)R^(a).

In some embodiments, each R^(a) is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(a) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹. In one variation, R^(a) is independently hydrogen or C₁₋₆ alkyl.

In some embodiments, each R^(b) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(b) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹. In one variation, R^(b) is independently hydrogen or C₁₋₆ alkyl.

In some embodiments, each R^(c) and R^(d) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(c) and R^(d) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹; or R^(c) and R^(d) are taken together with the nitrogen atom to which they are attached to form a 4- to 12-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹. In one variation, each R^(c) and R^(d) is independently hydrogen or C₁₋₆ alkyl.

In some embodiments, each R^(e) is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(e) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹. In one variation, R^(e) is independently C₁₋₆ alkyl.

In some embodiments, each R^(f2) is independently hydrogen or C₁₋₆ alkyl. In one variation, R^(f2) is hydrogen.

In some embodiments, each R¹¹ is independently oxo, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 8-membered heterocyclyl, halogen, cyano, —C(O)R^(a1), —C(O)OR^(b1), —C(O)NR^(c1)R^(d1), —OR^(b1), —OC(O)R^(a1), —OC(O)NR^(c1)R^(d1), —SR^(b1), —S(O)R^(e1), —S(O)₂R^(e1), —S(O)₂NR^(c1)R^(d1), —NR^(c1)R^(d1), —N(R^(f1))C(O)R^(a1), —N(R^(f1))C(O)OR^(b1), —N(R^(f1))C(O)NR^(c1)R^(d1), —N(R^(f1))S(O)₂R^(e1), or —N(R^(f1))S(O)₂NR^(c1)R^(d1); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R¹¹ are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹².

In one variation, each R¹¹ is independently oxo, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, 3- to 8-membered heterocyclyl, halogen, cyano, or —OR^(b1); wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, and 3- to 14-membered heterocyclyl of R¹¹ are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹².

In one variation, R¹¹ is C₁₋₆ alkyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹². In one variation, R¹¹ is 3- to 8-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹².

In one variation, R¹¹ is halogen, cyano, —NR^(c1)R^(d1), —C(O)NR^(c1)R^(d1), —OR^(b1), —S(O)₂R^(e1), C₁₋₆ haloalkyl, —(C₁₋₆ alkylene)-OH, or —(C₁₋₆ alkylene)-OH.

In one variation, R¹¹ is hydroxyl, cyano, halogen, —CHF₂, —CF₃, —NH₂, —NH(C₁₋₆ alkyl), —N(C₁₋₆ alkyl)₂, —O(C₁₋₆ alkyl), —SO₂(C₁₋₆ alkyl), —S(O)₂NR^(c1)R^(d1), —C(O)NR^(c1)R^(d1), or —N(R^(f1))C(O)R^(a1).

In one variation, R¹¹ is halogen, cyano, —O(C₁₋₆ alkyl), —O(C₁₋₆ alkylene)-NH₂, or —(C₁₋₆ alkylene)-OH.

In some embodiments, each R^(a1) is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(a1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹².

In some embodiments, each R^(b1) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆-10 aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(b1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹². In one variation, R^(b1) is independently hydrogen or C₁₋₆ alkyl.

In some embodiments, each R^(c1) and R^(d1) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(c1) and R^(d1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²; or R^(c1) and R^(d1) are taken together with the nitrogen atom to which they are attached to form a 4- to 8-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹². In one variation, each R^(c1) and R^(d1) is independently hydrogen or C₁₋₆ alkyl.

In some embodiments, each R^(e1) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(e1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹². In one variation, R^(e1) is independently C₁₋₆ alkyl.

In some embodiments, each R^(f1) is independently hydrogen or C₁₋₆ alkyl. In one variation, R^(f1) is hydrogen.

In some embodiments, each R¹² is independently oxo, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl, 3- to 6-membered heterocyclyl, halogen, cyano, —C(O)R^(a2), —C(O)OR^(b2), —C(O)NR^(c2)R^(d2), —OR^(b2), —OC(O)R^(a2), —OC(O)NR^(c2)R^(d2), —S(O)₂R^(e2), —S(O)₂NR^(c2)R^(d2), —NR^(c2)R^(d2), —N(R^(f2))C(O)R^(a2), —N(R^(f2))C(O)OR^(b2), —N(R^(f2))C(O)NR^(c2)R^(d2), —N(R^(f2))S(O)₂R^(e2), or —N(R^(f2))S(O)₂NR^(c2)R^(d2); wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R¹² are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³.

In one variation, each R¹² is independently oxo, halogen, cyano, —OR^(b2), or C₁₋₆ alkyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³. In one variation, each R¹² is independently oxo, halogen, cyano, or hydroxyl.

In one variation, R¹² is C₁₋₆ alkyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³.

In one variation, R¹² is oxo, hydroxyl, C₁₋₆ alkyl, or —O(C₁₋₆ alkyl).

In some embodiments, each R^(a2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R^(a2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³. In one variation, R^(a2) is independently hydrogen or C₁₋₆ alkyl.

In some embodiments, each R^(b2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl and 3- to 6-membered heterocyclyl of R^(b2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³. In one variation, R^(b2) is hydrogen.

In some embodiments, each R^(c2) and R^(d2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl and 3- to 8-membered heterocyclyl of R^(c2) and R^(d2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³; or R^(c2) and R^(d2) are taken together with the nitrogen atom to which they are attached to form a 4- to 6-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³. In one variation, each R^(c2) and R^(d2) is independently hydrogen or C₁₋₆ alkyl.

In some embodiments, each R^(e2) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R^(e2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³. In one variation, R^(e2) is independently C₁₋₆ alkyl.

In some embodiments, each R^(f2) is independently hydrogen or C₁₋₆ alkyl. In one variation, R^(f2) is hydrogen.

In some embodiments, each R¹³ is independently oxo, halogen, hydroxyl, —O(C₁₋₆ alkyl), cyano, C₁₋₆ alkyl or C₁₋₆ haloalkyl.

In one variation, each R¹³ is independently halogen, hydroxyl, —O(C₁₋₆ alkyl), cyano, or C₁₋₆ alkyl.

In one variation, R¹³ is oxo, hydroxyl, C₁₋₆ alkyl, or —O(C₁₋₆ alkyl).

Representative compounds are listed in Table 1. It is understood that individual enatiomers and diastereomers are included in the table below by Compound No. and Compound Name, and their corresponding structures can be readily determined therefrom. In some instances, the enantiomers or diastereomers are identified by their respective properties, for example, retention times on a chiral HPLC or its biological activities, and the absolute stereo configurations of the chiral centers are arbitrarily assigned.

TABLE 1 Cpd. No. Structure Name 101

2'-((6-(5-amino-4-methylpyridin-3-yl)-8- methyl-2,7-naphthyridin-3-yl)amino)- 6'-methyl-5',6'- dihydrospiro[cyclopropane-1,4'- pyrazolo[1,5-d][1,4]diazepin]-7'(8'H)- one 102

2-((6-(5-amino-4-methylpyridin-3-yl)- 2,7-naphthyridin-3-yl)amino)-6-(2,2- difluoroethyl)-5,6-dihydro-4H- pyrazolo[1,5-d][1,4]diazepin-7(8H)-one 103

6-isopropyl-2-((6-(8-methyl-2,3-dihydro- 1H-pyrido[2,3-b][1,4]oxazin-7-yl)-2,7- naphthyridin-3-yl)amino)-5,6-dihydro- 4H-pyrazolo[1,5-d][1,4]diazepin-7(8H)- one 104

2-((6-(5-amino-4-methylpyridin-3-yl)- 2,7-naphthyridin-3-yl)amino)-6- isopropyl-5,6-dihydro-4H-pyrazolo[1,5- d][1,4]diazepin-7(8H)-one 105

N-(6-(5-amino-4-methylpyridin-3-yl)-8- methyl-2,7-naphthyridin-3-yl)-5,6- dihydro-11H-imidazo[1,2-a]pyrazolo [1,5-d][1,4]diazepin-8-amine 106

2-((6-(5-amino-4-methylpyridin-3-yl)-8- methyl-2,7-naphthyridin-3-yl)amino)-6- isopropyl-5,6-dihydro-4H-pyrazolo[1,5- d][1,4]diazepin-7(8H)-one 107

2-((8-methoxy-6-(8-methyl-2,3-dihydro- 1H-pyrido[2,3-b][1,4]oxazin-7-yl)-2,7- naphthyridin-3-yl)amino)-6-methyl-5,6- dihydro-4H-pyrazolo[1,5- d][1,4]diazepin-7(8H)-one 108

6-methyl-2-((8-methyl-6-(8-methyl-2,3- dihydro-1H-pyrido[2,3-b][1,4]oxazin-7- yl)-2,7-naphthyridin-3-yl)amino)-5,6- dihydro-4H-pyrazolo[1,5- d][1,4]diazepin-7(8H)-one 109

6'-methyl-2'-((8-methyl-6-(8-methyl-2,3- dihydro-1H-pyrido[2,3-b][1,4]oxazin-7- yl)-2,7-naphthyridin-3-yl)amino)-5',6'- dihydrospiro[cyclopropane-1,4'- pyrazolo[1,5-d][1,4]diazepin]- 7'(8'H)-one 110

2-((6-(2-fluoro-6-methyl-4- ((methylamino)methyl)phenyl)-2,7- naphthyridin-3-yl)amino)-6-methyl-5,6- dihydro-4H-pyrazolo[1,5- d][1,4]diazepin-7(8H)-one 111

2-[[8-amino-6-(4-methyl-3-pyridyl)-2,7- naphthyridin-3-yl]amino]-5,7-dimethyl- 9H-pyrido[2,3-d]azepin-8-one 201

5-amino-N,N-dimethyl-2-((6-(4- methylpyridin-3-yl)-2,7-naphthyridin-3- yl)amino)isonicotinamide 202

6-(4-methylpyridin-3-yl)-N-(5- (methylsulfonyl)pyridin-2-yl)-2,7- naphthyridin-3-amine 203

6-((6-(4-methylpyridin-3-yl)-2,7- naphthyridin-3-yl)amino)pyridine-3- sulfonamide 204

N,N-dimethyl-6-((6-(4-methylpyridin-3- yl)-2,7-naphthyridin-3- yl)amino)nicotinamide 205

2-(6-((6-(4-methylpyridin-3-yl)-2,7- naphthyridin-3-yl)amino)pyridin-3- yl)acetonitrile 206

(6-((6-(4-methylpyridin-3-yl)-2,7- naphthyridin-3-yl)amino)pyridin-3- yl)methanol 207

N-methyl-6-((6-(4-methylpyridin-3-yl)- 2,7-naphthyridin-3-yl)amino)pyridine-3- sulfonamide 208

2-(6-((6-(4-methylpyridin-3-yl)-2,7- naphthyridin-3-yl)amino)pyridin-3- yl)ethan-1-ol 209

6-cyclopropyl-N-(6-methylpyrimidin-4- yl)-2,7-naphthyridin-3-amine 210

6-methyl-N⁴-(6-(4-methylpyridin-3-yl)- 2,7-naphthyridin-3-yl)pyrimidine-2,4- diamine

In some embodiments, provided is a compound selected from Compound Nos. 101-111 and 201-210 in Table 1, or a salt (e.g., a pharmaceutically acceptable salt) thereof. In some embodiments, provided is a compound selected from Compound Nos. 101-111 in Table 1, or a salt (e.g., a pharmaceutically acceptable salt) thereof. In some embodiments, provided is a compound selected from Compound Nos. 201-210 in Table 1, or a salt (e.g., a pharmaceutically acceptable salt) thereof.

Compounds of Formula (I) described herein or a salt thereof may exist in stereoisomeric forms (e.g., it contains one or more asymmetric carbon atoms). The individual stereoisomers (enantiomers and diastereomers) and mixtures of these are included within the scope of the subject matter disclosed herein. Likewise, it is understood that a compound or salt of Formulas (I) may exist in tautomeric forms other than that shown in the formula and these are also included within the scope of the subject matter disclosed herein. It is to be understood that the subject matter disclosed herein includes combinations and subsets of the particular groups described herein. The scope of the subject matter disclosed herein includes mixtures of stereoisomers as well as purified enantiomers or enantiomerically/diastereomerically enriched mixtures. It is to be understood that the subject matter disclosed herein includes combinations and subsets of the particular groups defined herein.

The subject matter disclosed herein also includes isotopically-labelled forms of the compounds described herein, but for the fact that one or more atoms are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number usually found in nature. Examples of isotopes that can be incorporated into compounds described herein and pharmaceutically acceptable salts thereof include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorous, sulphur, fluorine, iodine, and chlorine, such as ²H, ³H, ¹¹C, ¹³C, ¹⁴C, ¹⁵N, ¹⁷O, ¹⁸O, ³¹P, ³²P, ³⁵S, ¹⁸F, ³⁶Cl, ¹²³I and ¹²⁵I.

The subject matter disclosed herein includes prodrugs, metabolites, derivatives, and pharmaceutically acceptable salts of compounds of Formula (I). Metabolites of the compounds of Formula (I) include compounds produced by a process comprising contacting a compound of Formula (I) with a mammal for a period of time sufficient to yield a metabolic product thereof.

If the compound of Formula (I) is a base, the desired pharmaceutically acceptable salt may be prepared by any suitable method available in the art, for example, treatment of the free base with an inorganic acid, such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, methanesulfonic acid, phosphoric acid and the like, or with an organic acid, such as acetic acid, maleic acid, succinic acid, mandelic acid, fumaric acid, malonic acid, pyruvic acid, oxalic acid, glycolic acid, salicylic acid, a pyranosidyl acid, such as glucuronic acid or galacturonic acid, an alpha hydroxy acid, such as citric acid or tartaric acid, an amino acid, such as aspartic acid or glutamic acid, an aromatic acid, such as benzoic acid or cinnamic acid, a sulfonic acid, such as p-toluenesulfonic acid or ethanesulfonic acid, or the like.

If the compound of Formula (I) is an acid, the desired pharmaceutically acceptable salt may be prepared by any suitable method, for example, treatment of the free acid with an inorganic or organic base, such as an amine (primary, secondary or tertiary), an alkali metal hydroxide or alkaline earth metal hydroxide, or the like. Illustrative examples of suitable salts include, but are not limited to, organic salts derived from amino acids, such as glycine and arginine, ammonia, primary, secondary, and tertiary amines, and cyclic amines, such as piperidine, morpholine and piperazine, and inorganic salts derived from sodium, calcium, potassium, magnesium, manganese, iron, copper, zinc, aluminum and lithium.

A compound of Formula (I) can be in the form of a “prodrug,” which includes compounds with moieties which can be metabolized in vivo. Generally, the prodrugs are metabolized in vivo by esterases or by other mechanisms to active drugs. Examples of prodrugs and their uses are well known in the art (See, e.g., Berge et al. (1977) “Pharmaceutical Salts”, J. Pharm. Sci. 66:1-19). The prodrugs can be prepared in situ during the final isolation and purification of the compounds, or by separately reacting the purified compound in its free acid form or hydroxyl with a suitable esterifying agent. Hydroxyl groups can be converted into esters via treatment with a carboxylic acid. Examples of prodrug moieties include substituted and unsubstituted, branch or unbranched lower alkyl ester moieties, (e.g., propionoic acid esters), lower alkenyl esters, di-lower alkyl-amino lower-alkyl esters (e.g., dimethylaminoethyl ester), acylamino lower alkyl esters (e.g., acetyloxymethyl ester), acyloxy lower alkyl esters (e.g., pivaloyloxymethyl ester), aryl esters (phenyl ester), aryl-lower alkyl esters (e.g., benzyl ester), substituted (e.g., with methyl, halo, or methoxy substituents) aryl and aryl-lower alkyl esters, amides, lower-alkyl amides, di-lower alkyl amides, and hydroxy amides. Prodrugs which are converted to active forms through other mechanisms in vivo are also included. In aspects, the compounds of the invention are prodrugs of any of the formulae herein.

General Synthetic Method

Compounds of Formula (I) can be prepared by procedures in the Examples and generally by Schemes 1 and 2, where R groups are as described in Formula (I), or precursors thereof.

Scheme 1 shows a general synthetic scheme for preparing a compound of Formula (I), wherein R¹, R², R³ and R⁴ are as detailed herein, from a compound of Formula 2, which in term can be prepared from a compound of Formula 1, wherein X⁴ is a halogen (e.g., Cl, Br or I). Installation of R⁴ can be achieved via a Suzuki coupling a compound of Formula 1 with the corresponding boronic acid or boronate pinacol ester of the formula R⁴—B(OR)₂, where R is H, optionally substituted C₁₋₆ alkyl, or the two OR groups taken together with the boron atom to which they are attached form a ring (e.g., pinacol boronate), using a palladium-based catalyst (e.g., Pd(dppf)Cl₂ or (Ph₃P)₄Pd) in the presence of a base (e.g. sodium carbonate or potassium acetate) in a solvent (e.g. 1,4-dioxane and water or acetonitrile and water). R² is then installed via a Pd-catalyzed coupling of a compound of Formula 2 with corresponding aryl or heteroaryl halide of the formula R²—X² (where X² is Cl, Br or I) in the presence of a catalyst (e.g., tBuBrettPhos Pd G₃ or XantPhos/Pd₂(dba)₃), a base (e.g. cesium carbonate) and a solvent (e.g. 1,4-dioxane).

Provided is a method for making a compound of Formula (I):

or a salt thereof, wherein R¹, R², R³ and R⁴ are as detailed herein, comprising reacting a compound of Formula 2:

or a salt thereof, wherein R¹, R³ and R⁴ are as defined for the Formular (I), optionally in a protected form thereof, with a compound of the formula R²—X², where X² is Cl, Br or I, in the presence of a Pd catalyst (e.g., tBuBrettPhos Pd G₃ or XantPhos/Pd₂(dba)₃), a base (e.g. cesium carbonate) and a solvent (e.g. 1,4-dioxane). In some embodiments, the reaction is performed at an elevated temperature, for example, about 80-100° C.

In some embodiments, the method further comprises reacting a compound of the Formula 1:

or a salt thereof, wherein R¹ and R³ are as defined for the Formular (I) or Formula 2, optionally in a protected form thereof, with a compound of the formula R⁴—B(OR)₂, wherein R is H, optionally substituted C₁₋₆ alkyl, or the two OR groups taken together with the boron atom to which they are attached form a ring (e.g., pinacol boronate), in the presence of a catalyst for Suzuki coupling (e.g., Pd(dppf)Cl₂ or (Ph₃P)₄Pd), a base (e.g. sodium carbonate or potassium acetate), and a solvent (e.g. 1,4-dioxane and water or acetonitrile and water), to form a compound of Formula 2. In some embodiments, the Suzuki coupling reaction is performed at an elevated temperature, for example, about 100-120° C.

Scheme 2 shows an example of the general synthetic method as in Scheme 1, where in the compound of Formula (I), R² is an optionally substituted heteroaryl, R³ is hydrogen, and R⁴ is an optionally substituted heteroaryl; in the compound of Formula 1, X⁴ is chloro; in the step of the Suzuki coupling reaction forming the compound of Formula 2, the catalyst for Suzuki coupling is Pd(dppf)Cl₂, the base is potassium carbonate, and the solvent is 1,4-dioxane and water; and in the step of the palladium-catalyzed coupling reaction forming the compound of Formula (I), the Pd catalyst is tBuBrettPhos Pd G₃ or XantPhos/Pd₂(dba)₃), the base is cesium carbonate, and the solvent solvent is 1,4-dioxane.

Pharmaceutical Compositions and Formulations

The presently disclosed compounds can be formulated into pharmaceutical compositions along with a pharmaceutically acceptable carrier or excipient.

Compounds of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), can be formulated in accordance with standard pharmaceutical practice as a pharmaceutical composition. According to this aspect, there is provided a pharmaceutical composition comprising a compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), in association with a pharmaceutically acceptable excipient, diluent or carrier.

A typical formulation is prepared by mixing a compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), and a carrier, diluent or excipient. Suitable carriers, diluents and excipients are well known to those skilled in the art and include materials such as carbohydrates, waxes, water soluble and/or swellable polymers, hydrophilic or hydrophobic materials, gelatin, oils, solvents, water and the like. The particular carrier, diluent or excipient used will depend upon the means and purpose for which the compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), is being applied. Solvents are generally selected based on solvents recognized by persons skilled in the art as safe (GRAS) to be administered to a mammal. In general, safe solvents are non-toxic aqueous solvents such as water and other non-toxic solvents that are soluble or miscible in water. Suitable aqueous solvents include water, ethanol, propylene glycol, polyethylene glycols (e.g., PEG 400, PEG 300), etc. and mixtures thereof. The formulations may also include one or more buffers, stabilizing agents, surfactants, wetting agents, lubricating agents, emulsifiers, suspending agents, preservatives, antioxidants, opaquing agents, glidants, processing aids, colorants, sweeteners, perfuming agents, flavoring agents and other known additives to provide an elegant presentation of the drug (i.e., a compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or pharmaceutical composition thereof) or aid in the manufacturing of the pharmaceutical product (i.e., medicament).

The formulations may be prepared using conventional dissolution and mixing procedures. For example, the bulk drug substance (i.e., compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or stabilized form of the Compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), (e.g., complex with a cyclodextrin derivative or other known complexation agent) is dissolved in a suitable solvent in the presence of one or more of the excipients described above. The compound of Formula (I) is typically formulated into pharmaceutical dosage forms to provide an easily controllable dosage of the drug and to enable patient compliance with the prescribed regimen.

The pharmaceutical composition (or formulation) for application may be packaged in a variety of ways depending upon the method used for administering the drug. Generally, an article for distribution includes a container having deposited therein the pharmaceutical formulation in an appropriate form. Suitable containers are well known to those skilled in the art and include materials such as bottles (plastic and glass), sachets, ampoules, plastic bags, metal cylinders, and the like. The container may also include a tamper-proof assemblage to prevent indiscreet access to the contents of the package. In addition, the container has deposited thereon a label that describes the contents of the container. The label may also include appropriate warnings.

Pharmaceutical formulations may be prepared for various routes and types of administration. For example, a compound of Formula (I) having the desired degree of purity may optionally be mixed with pharmaceutically acceptable diluents, carriers, excipients or stabilizers (Remington's Pharmaceutical Sciences (1980) 16^(th) edition, Osol, A. Ed.), in the form of a lyophilized formulation, milled powder, or an aqueous solution. Formulation may be conducted by mixing at ambient temperature at the appropriate pH, and at the desired degree of purity, with physiologically acceptable excipients or carriers, i.e., excipients or carriers that are non-toxic to recipients at the dosages and concentrations employed. The pH of the formulation depends mainly on the particular use and the concentration of compound, but may range from about 3 to about 8. Formulation in an acetate buffer at pH 5 is a suitable embodiment.

The compounds of Formula (I) can be sterile. In particular, formulations to be used for in vivo administration should be sterile. Such sterilization is readily accomplished by filtration through sterile filtration membranes.

The compound ordinarily can be stored as a solid composition, a lyophilized formulation or as an aqueous solution.

The pharmaceutical compositions comprising a compound of Formula (I) can be formulated, dosed and administered in a fashion, i.e., amounts, concentrations, schedules, course, vehicles and route of administration, consistent with good medical practice. Factors for consideration in this context include the particular disorder being treated, the particular mammal being treated, the clinical condition of the individual patient, the cause of the disorder, the site of delivery of the agent, the method of administration, the scheduling of administration, and other factors known to medical practitioners. The “therapeutically effective amount” of the compound to be administered will be governed by such considerations, and is the minimum amount necessary to prevent, ameliorate, or treat the coagulation factor mediated disorder. In some embodiments, the amount is below the amount that is toxic to the host or renders the host more susceptible to bleeding.

Acceptable diluents, carriers, excipients and stabilizers are nontoxic to recipients at the dosages and concentrations employed, and include buffers such as phosphate, citrate and other organic acids; antioxidants including ascorbic acid and methionine; preservatives (such as octadecyldimethylbenzyl ammonium chloride; hexamethonium chloride; benzalkonium chloride, benzethonium chloride; phenol, butyl or benzyl alcohol; alkyl parabens such as methyl or propyl paraben; catechol; resorcinol; cyclohexanol; 3-pentanol; and m-cresol); low molecular weight (less than about 10 residues) polypeptides; proteins, such as serum albumin, gelatin, or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone; amino acids such as glycine, glutamine, asparagine, histidine, arginine, or lysine; monosaccharides, disaccharides and other carbohydrates including glucose, mannose, or dextrins; chelating agents such as EDTA; sugars such as sucrose, mannitol, trehalose or sorbitol; salt-forming counter-ions such as sodium; metal complexes (e.g., Zn-protein complexes); and/or non-ionic surfactants such as TWEEN™, PLURONICS™ or polyethylene glycol (PEG). The active pharmaceutical ingredients may also be entrapped in microcapsules prepared, for example, by coacervation techniques or by interfacial polymerization, for example, hydroxymethylcellulose or gelatin-microcapsules and poly-(methylmethacylate) microcapsules, respectively, in colloidal drug delivery systems (for example, liposomes, albumin microspheres, microemulsions, nano-particles and nanocapsules) or in macroemulsions. Such techniques are disclosed in Remington's Pharmaceutical Sciences 16^(th) edition, Osol, A. Ed. (1980).

Sustained-release preparations of Formula (I) compounds may be prepared. Suitable examples of sustained-release preparations include semipermeable matrices of solid hydrophobic polymers containing a compound of Formula (I) or Ia, which matrices are in the form of shaped articles, e.g., films, or microcapsules. Examples of sustained-release matrices include polyesters, hydrogels (for example, poly(2-hydroxyethyl-methacrylate), or poly(vinyl alcohol)), polylactides (U.S. Pat. No. 3,773,919), copolymers of L-glutamic acid and gamma-ethyl-L-glutamate, non-degradable ethylene-vinyl acetate, degradable lactic acid-glycolic acid copolymers such as the LUPRON DEPOT™ (injectable microspheres composed of lactic acid-glycolic acid copolymer and leuprolide acetate) and poly-D-(−)-3-hydroxybutyric acid.

The formulations include those suitable for the administration routes detailed herein. The formulations may conveniently be presented in unit dosage form and may be prepared by any of the methods well known in the art of pharmacy. Techniques and formulations generally are found in Remington's Pharmaceutical Sciences (Mack Publishing Co., Easton, Pa.). Such methods include the step of bringing into association the active ingredient with the excipient or carrier which constitutes one or more accessory ingredients. In general the formulations are prepared by uniformly and intimately bringing into association the active ingredient with liquid excipients or carriers or finely divided solid excipients or carriers or both, and then, if necessary, shaping the product.

Formulations of a compound of Formula (I) suitable for oral administration may be prepared as discrete units such as pills, capsules, cachets or tablets each containing a predetermined amount of a compound of Formula (I) or Ia.

Compressed tablets may be prepared by compressing in a suitable machine the active ingredient in a free-flowing form such as a powder or granules, optionally mixed with a binder, lubricant, inert diluent, preservative, surface active or dispersing agent. Molded tablets may be made by molding in a suitable machine a mixture of the powdered active ingredient moistened with an inert liquid diluent. The tablets may optionally be coated or scored and optionally are formulated so as to provide slow or controlled release of the active ingredient therefrom.

Tablets, troches, lozenges, aqueous or oil suspensions, dispersible powders or granules, emulsions, hard or soft capsules, e.g., gelatin capsules, syrups or elixirs may be prepared for oral use. Formulations of compounds of Formula (I) intended for oral use may be prepared according to any method known to the art for the manufacture of pharmaceutical compositions and such compositions may contain one or more agents including sweetening agents, flavoring agents, coloring agents and preserving agents, in order to provide a palatable preparation. Tablets containing the active ingredient in admixture with non-toxic pharmaceutically acceptable excipient which are suitable for manufacture of tablets are acceptable. These excipients may be, for example, inert diluents, such as calcium or sodium carbonate, lactose, calcium or sodium phosphate; granulating and disintegrating agents, such as maize starch, or alginic acid; binding agents, such as starch, gelatin or acacia; and lubricating agents, such as magnesium stearate, stearic acid or talc. Tablets may be uncoated or may be coated by known techniques including microencapsulation to delay disintegration and adsorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distearate alone or with a wax may be employed.

For treatment of the eye or other external tissues, e.g., mouth and skin, the formulations are preferably applied as a topical ointment or cream containing the active ingredient(s) in an amount of, for example, 0.075 to 20% w/w. When formulated in an ointment, the active ingredients may be employed with either a paraffinic or a water-miscible ointment base. Alternatively, the active ingredients may be formulated in a cream with an oil-in-water cream base.

If desired, the aqueous phase of the cream base may include a polyhydric alcohol, i.e., an alcohol having two or more hydroxyl groups such as propylene glycol, butane 1,3-diol, mannitol, sorbitol, glycerol and polyethylene glycol (including PEG 400), and mixtures thereof. The topical formulations may desirably include a compound which enhances absorption or penetration of the active ingredient through the skin or other affected areas. Examples of such dermal penetration enhancers include dimethyl sulfoxide and related analogs.

The oily phase of the emulsions may be constituted from known ingredients in a known manner. While the phase may comprise solely an emulsifier, it may also comprise a mixture of at least one emulsifier and a fat or oil, or both a fat and an oil. A hydrophilic emulsifier included together with a lipophilic emulsifier may act as a stabilizer. Together, the emulsifier(s) with or without stabilizer(s) make up the so-called emulsifying wax, and the wax together with the oil and fat make up the so-called emulsifying ointment base which forms the oily dispersed phase of the cream formulations. Emulsifiers and emulsion stabilizers suitable for use in the formulation include Tween® 60, Span® 80, cetostearyl alcohol, benzyl alcohol, myristyl alcohol, glyceryl mono-stearate and sodium lauryl sulfate.

Aqueous suspensions of Formula (I) compounds contain the active materials in admixture with excipients suitable for the manufacture of aqueous suspensions. Such excipients include a suspending agent, such as sodium carboxymethylcellulose, croscarmellose, povidone, methylcellulose, hydroxypropyl methylcellulose, sodium alginate, polyvinylpyrrolidone, gum tragacanth and gum acacia, and dispersing or wetting agents such as a naturally occurring phosphatide (e.g., lecithin), a condensation product of an alkylene oxide with a fatty acid (e.g., polyoxyethylene stearate), a condensation product of ethylene oxide with a long chain aliphatic alcohol (e.g., heptadecaethyleneoxycetanol), a condensation product of ethylene oxide with a partial ester derived from a fatty acid and a hexitol anhydride (e.g., polyoxyethylene sorbitan monooleate). The aqueous suspension may also contain one or more preservatives such as ethyl or n-propyl p-hydroxybenzoate, one or more coloring agents, one or more flavoring agents and one or more sweetening agents, such as sucrose or saccharin.

The pharmaceutical compositions of compounds of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), may be in the form of a sterile injectable preparation, such as a sterile injectable aqueous or oleaginous suspension. This suspension may be formulated according to the known art using those suitable dispersing or wetting agents and suspending agents which have been mentioned above. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally acceptable diluent or solvent, such 1,3-butanediol. The sterile injectable preparation may also be prepared as a lyophilized powder. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile fixed oils may conventionally be employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid may likewise be used in the preparation of injectables.

The amount of active ingredient that may be combined with the excipient or carrier material to produce a single dosage form will vary depending upon the host treated and the particular mode of administration. For example, a time-release formulation intended for oral administration to humans may contain approximately 1 to 1000 mg of active material compounded with an appropriate and convenient amount of excipient or carrier material which may vary from about 5 to about 95% of the total compositions (weight:weight). The pharmaceutical composition can be prepared to provide easily measurable amounts for administration. For example, an aqueous solution intended for intravenous infusion may contain from about 3 to 500 μg of the active ingredient per milliliter of solution in order that infusion of a suitable volume at a rate of about 30 mL/hr can occur.

Formulations suitable for parenteral administration include aqueous and non-aqueous sterile injection solutions which may contain anti-oxidants, buffers, bacteriostats and solutes which render the formulation isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents and thickening agents.

Formulations suitable for topical administration to the eye also include eye drops wherein the active ingredient is dissolved or suspended in a suitable excipient or carrier, especially an aqueous solvent for the active ingredient. The active ingredient is preferably present in such formulations in a concentration of about 0.5 to 20% w/w, for example about 0.5 to 10% w/w, for example about 1.5% w/w.

Formulations suitable for topical administration in the mouth include lozenges comprising the active ingredient in a flavored basis, usually sucrose and acacia or tragacanth; pastilles comprising the active ingredient in an inert basis such as gelatin and glycerin, or sucrose and acacia; and mouthwashes comprising the active ingredient in a suitable liquid carrier.

Formulations for rectal administration may be presented as a suppository with a suitable base comprising for example cocoa butter or a salicylate.

Formulations suitable for intrapulmonary or nasal administration have a particle size for example in the range of 0.1 to 500 microns (including particle sizes in a range between 0.1 and 500 microns in increments microns such as 0.5, 1, 30 microns, 35 microns, etc.), which is administered by rapid inhalation through the nasal passage or by inhalation through the mouth so as to reach the alveolar sacs. Suitable formulations include aqueous or oily solutions of the active ingredient. Formulations suitable for aerosol or dry powder administration may be prepared according to conventional methods and may be delivered with other therapeutic agents such as compounds heretofore used in the treatment or prophylaxis of disorders as described below.

Formulations suitable for vaginal administration may be presented as pessaries, tampons, creams, gels, pastes, foams or spray formulations containing in addition to the active ingredient such excipients or carriers as are known in the art to be appropriate.

The formulations may be packaged in unit-dose or multi-dose containers, for example sealed ampoules and vials, and may be stored in a freeze-dried (lyophilized) condition requiring only the addition of the sterile liquid excipient or carrier, for example water, for injection immediately prior to use. Extemporaneous injection solutions and suspensions are prepared from sterile powders, granules and tablets of the kind previously described. Preferred unit dosage formulations are those containing a daily dose or unit daily sub-dose, as herein above recited, or an appropriate fraction thereof, of the active ingredient.

The subject matter further provides veterinary compositions comprising at least one active ingredient as above defined together with a veterinary excipient or carrier therefore. Veterinary excipients or carriers are materials useful for the purpose of administering the composition and may be solid, liquid or gaseous materials which are otherwise inert or acceptable in the veterinary art and are compatible with the active ingredient. These veterinary compositions may be administered parenterally, orally or by any other desired route.

In particular embodiments the pharmaceutical composition comprising the presently disclosed compounds further comprise a chemotherapeutic agent. In some of these embodiments, the chemotherapeutic agent is an immunotherapeutic agent.

Methods of Use

The presently disclosed compounds find use in inhibiting the activity of the enzyme HPK1. HPK1, also referred to as mitogen activated protein kinase kinase kinase kinase 1 or MAP4K1, is a member of the germinal center kinase subfamily of Ste20-related serine/threnonine kinases. HPK1 functions as a MAP4K by phosphorylating and activating MAP3K proteins, including MEKK1, MLK3 and TAK1, leading to the activation of the MAPK Jnk.

In an embodiment, the subject matter disclosed herein is directed to a method of inhibiting HPK1, the method comprising contacting HPK1 with an effective amount of a compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutical composition described herein.

In an embodiment, the subject matter disclosed herein is directed to a method for enhancing an immune response in a subject in need thereof, wherein the method comprises administering to said subject an effective amount of a compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutical composition described herein. In certain aspects of this embodiment, the T cells in the subject have at least one of enhanced priming, enhanced activation, enhanced migration, enhanced proliferation, enhanced survival, and enhanced cytolytic activity relative to prior to the administration of the compound or pharmaceutical composition. In certain aspects of this embodiment, the T cell activation is characterized by an elevated frequency of γ-IFN+CD8 T cells, an elevated frequency of γ-IFN+CD4 T cells, or enhanced levels of IL-2 or granzyme B production by T cells, relative to prior to administration of the compound or pharmaceutical composition. In certain aspects of this embodiment, the number of T cells is elevated relative to prior to administration of the compound or pharmaceutical composition. In certain aspects of this embodiment, the T cell is an antigen-specific CD8 T cell. In certain aspects of this embodiment, the T cell is an antigen-specific CD4 T cell. In certain aspects of this embodiment, the antigen presenting cells in the subject have enhanced maturation and activation relative prior to the administration of the compound or pharmaceutical composition. In certain aspects of this embodiment, the antigen presenting cells are dendritic cells. In certain aspects of this embodiment, the maturation of the antigen presenting cells is characterized by increased frequency of CD83+ dendritic cells. In certain aspects of this embodiment, the activation of the antigen presenting cells is characterized by elevated expression of CD80 and CD86 on dendritic cells. In some aspects, compounds of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutical composition thereof provides general priming of the immune response (i.e., vaccines) to tumors or viruses for boosting/generating anti-viral/tumor immunity.

In the methods described herein, a compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutical composition thereof is administered to a subject that has cancer as described elsewhere herein.

In an embodiment, the subject matter disclosed herein is directed to a method for treating a HPK1-dependent disorder, the method comprising administering to a subject in need thereof an effective amount of a compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutical composition described herein. In certain aspects of this embodiment, the HPK1-dependent disorder is a cancer. In certain aspects of this embodiment, the cancer comprises at least one cancer selected from the group consisting of colorectal cancer, melanoma, non-small cell lung cancer, ovarian cancer, breast cancer, pancreatic cancer, a hematological malignancy, and a renal cell carcinoma. In certain aspects of this embodiment, the cancer has elevated levels of T-cell infiltration. In certain aspects of this embodiment, the cancer cells in the subject selectively have elevated expression of MHC class I antigen expression relative to prior to the administration of the compound or composition.

In the methods described herein, the method can further comprise administering a chemotherapeutic agent to said subject. In certain aspects of this embodiment, the chemotherapeutic agent is administered to the subject simultaneously with the compound or the composition. In certain aspects of this embodiment, the chemotherapeutic agent is administered to the subject prior to administration of the compound or the composition. In certain aspects of this embodiment, the chemotherapeutic agent is administered to the subject after administration of the compound or said composition.

HPK1 polynucleotides and polypeptides are known in the art (Hu et al. (1996) Genes Dev. 10: 2251-2264, which is herein incorporated by reference in its entirety). Certain HPK1 polynucleotides and polypeptides comprise the human HPK1 polynucleotide are accessible and the sequences are known, for example, nucleotides 141-2642 of GenBank Accession No. NM_007181.5 and the encoded human HPK1 polypeptide (Accession No. NP_009112.1); and nucleotides 141-2606 of GenBank Accession No. NM_001042600.2 and the encoded human HPK1 polypeptide (Accession No. NP_001036065.1).

HPK1 polypeptides comprise a variety of conserved structural motifs. HPK1 polypeptides comprise an amino-terminal Ste20-like kinase domain, which includes the ATP-binding site. The kinase domain is followed by four proline-rich (PR) motifs that serve as binding sites for SH3-containing proteins, such as CrkL, Grb2, HIP-55, Gads, Nck, and Crk. HPK1 becomes phosphorylated and activated in response to TCR or BCR stimulation. TCR- and BCR-induced phosphorylation of a tyrosine residue located between PR1 and PR2, mediates binding to SLP-76 in T cells or BLNK in B cells via a SLP-76 or BLNK SH2 domain, and is required for activation of the kinase. A citron homology domain found in the C-terminus of HPK1 may act as a regulatory domain and may be involved in macromolecular interactions.

The presently disclosed compounds bind directly to HPK1 and inhibit its kinase activity. In some embodiments, the presently disclosed compounds reduce, inhibit, or otherwise diminish the HPK1-mediated phosphorylation of SLP76 and/or Gads.

The presently disclosed compounds may or may not be a specific HPK1 antagonist. A specific HPK1 antagonist reduces the biological activity of HPK1 by an amount that is statistically greater than the inhibitory effect of the antagonist on any other protein (e.g., other serine/threonine kinases). In certain embodiments, the presently disclosed compounds specifically inhibit the serine/threonine kinase activity of HPK1. In some of these embodiments, the IC₅₀ of the HPK1 antagonist for HPK1 is about 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, 0.1%, 0.01%, 0.001%, or less of the IC₅₀ of the HPK1 antagonist for another serine/threonine kinase or other type of kinase (e.g., tyrosine kinase).

The presently disclosed compounds can be used in a method for inhibiting HPK1. Such methods comprise contacting HPK1 with an effective amount of a presently disclosed compound. By “contact” is intended bringing the compound within close enough proximity to an isolated HPK1 enzyme or a cell expressing HPK1 (e.g., T cell, B cell, dendritic cell) such that the compound is able to bind to and inhibit the activity of HPK1. The compound can be contacted with HPK1 in vitro or in vivo via administration of the compound to a subject.

Any method known in the art to measure the kinase activity of HPK1 may be used to determine if HPK1 has been inhibited, including in vitro kinase assays, immunoblots with antibodies specific for phosphorylated targets of HPK1, such as SLP76 and Gads, or the measurement of a downstream biological effect of HPK1 kinase activity, such as the recruitment of 14-3-3 proteins to phosphorylated SLP7 and Gads, release of the SLP76-Gads-14-3-3 complex from LAT-containing microclusters, or T or B cell activation.

The presently disclosed compounds can be used to treat a HPK1-dependent disorder. As used herein, a “HPK1-dependent disorder” is a pathological condition in which HPK1 activity is necessary for the genesis or maintenance of the pathological condition. In some embodiments, the HPK1-dependent disorder is cancer.

The presently disclosed compounds also find use in enhancing an immune response in a subject in need thereof. Such methods comprise administering an effective amount of a presently disclosed compound (i.e., compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutically acceptable salt, prodrug, metabolite, or derivative thereof).

As used herein, “enhancing an immune response” refers to an improvement in any immunogenic response to an antigen. Non-limiting examples of improvements in an immunogenic response to an antigen include enhanced maturation or migration of dendritic cells, enhanced activation of T cells (e.g., CD4 T cells, CD8 T cells), enhanced T cell (e.g., CD4 T cell, CD8 T cell) proliferation, enhanced B cell proliferation, increased survival of T cells and/or B cells, improved antigen presentation by antigen presenting cells (e.g., dendritic cells), improved antigen clearance, increase in production of cytokines by T cells (e.g., interleukin-2), increased resistance to prostaglandin E2-induced immune suppression, and enhanced priming and/or cytolytic activity of CD8 T cells.

In some embodiments, the CD8 T cells in the subject have enhanced priming, activation, proliferation and/or cytolytic activity relative to prior to the administration of the compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutically acceptable salt, prodrug, metabolite, or derivative thereof. In some embodiments, the CD8 T cell priming is characterized by elevated CD44 expression and/or enhanced cytolytic activity in CD8 T cells. In some embodiments, the CD8 T cell activation is characterized by an elevated frequency of γ-IFN⁺CD8 T cells. In some embodiments, the CD8 T cell is an antigen-specific T-cell.

In some embodiments, the CD4 T cells in the subject have enhanced priming, activation, proliferation and/or cytolytic activity relative to prior to the administration of the compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutically acceptable salt, prodrug, metabolite, or derivative thereof. In some embodiments, the CD4 T cell priming is characterized by elevated CD44 expression and/or enhanced cytolytic activity in CD4 T cells. In some embodiments, the CD4 T cell activation is characterized by an elevated frequency of γ-IFN⁺CD4 T cells. In some embodiments, the CD4 T cell is an antigen-specific T-cell.

In some embodiments, the antigen presenting cells in the subject have enhanced maturation and activation relative to prior to the administration of the compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutically acceptable salt, prodrug, metabolite, or derivative thereof. In some embodiments, the antigen presenting cells are dendritic cells. In some embodiments, the maturation of the antigen presenting cells is characterized by an increased frequency of CD83⁺ dendritic cells. In some embodiments, the activation of the antigen presenting cells is characterized by elevated expression of CD80 and CD86 on dendritic cells.

In some embodiments, the serum levels of cytokine IL-10 and/or chemokine IL-8, a human homolog of murine KC, in the subject are reduced relative to prior to the administration of the compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutically acceptable salt, prodrug, metabolite, or derivative thereof.

Engagement of the TCR leads to HPK1 activation, which functions as a negative regulator of TCR-induced AP-1 response pathway. It is believed that HPK1 negatively regulates T cell activation by reducing the persistence of signaling microclusters by phosphorylating SLP76 at Ser376 (Di Bartolo et al. (2007) JEM 204:681-691) and Gads at Thr254, which leads to the recruitment of 14-3-3 proteins that bind to the phosphorylated SLP76 and Gads, releasing the SLP76-Gads-14-3-3 complex from LAT-containing microclusters, which leads to T cell dysfunction, including anergy and exhaustion (Lasserre et al. (2011) J Cell Biol 195(5):839-853).

The term “dysfunction” in the context of immune dysfunction, refers to a state of reduced immune responsiveness to antigenic stimulation. The term includes the common elements of both exhaustion and/or anergy in which antigen recognition may occur, but the ensuing immune response is ineffective to control infection or tumor growthours.

The term “dysfunctional”, as used herein, also includes refractory or unresponsive to antigen recognition, specifically, impaired capacity to translate antigen recognition into downstream T-cell effector functions, such as proliferation, cytokine production (e.g., IL-2, γ-IFN) and/or target cell killing.

The term “anergy” refers to the state of unresponsiveness to antigen stimulation resulting from incomplete or insufficient signals delivered through the T-cell receptor (e.g. increase in intracellular Ca⁺² in the absence of ras-activation). T cell anergy can also result upon stimulation with antigen in the absence of co-stimulation, resulting in the cell becoming refractory to subsequent activation by the antigen even in the context of costimulation. The unresponsive state can often be overriden by the presence of Interleukin-2. Anergic T-cells do not undergo clonal expansion and/or acquire effector functions.

The term “exhaustion” refers to T cell exhaustion as a state of T cell dysfunction that arises from sustained TCR signaling that occurs during many chronic infections and cancer. It is distinguished from anergy in that it arises not through incomplete or deficient signaling, but from sustained signaling. It is defined by poor effector function, sustained expression of inhibitory receptors and a transcriptional state distinct from that of functional effector or memory T cells. Exhaustion prevents optimal control of infection and tumors. Exhaustion can result from both extrinsic negative regulatory pathways (e.g., immunoregulatory cytokines) as well as cell intrinsic negative regulatory (costimulatory) pathways (PD-1, B7-H3, B7-H4, etc.).

In some embodiments, administration of a compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutically acceptable salt, prodrug, metabolite, or derivative thereof to a subject results in an enhancement of T cell function. In some embodiments, administration of HPK1 inhibitors described herein may enhance/renew/reactivate immune response or activate de nove immune response.

“Enhancing T cell function” means to induce, cause or stimulate a T cell to have a sustained or amplified biological function, or renew or reactivate exhausted or inactive T cells. Examples of enhancing T cell function include: increased secretion of cytokines (e.g., γ-interferon, IL-2, IL-12, and TNFα), increased proliferation, increased antigen responsiveness (e.g., viral, pathogen, or tumor clearance) relative to such levels before the intervention, and increased effector granule production by CD8 T cells or CD4 T cells, such as granzyme B. In one embodiment, the level of enhancement is as least 50%, alternatively 60%, 70%, 80%, 90%, 100%, 120%, 150%, 200%. The manner of measuring this enhancement is known to one of ordinary skill in the art.

Accordingly, the presently disclosed compounds of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or pharmaceutically acceptable salts, prodrugs, metabolites, or derivatives thereof are useful in treating T cell dysfunctional disorders. A “T cell dysfunctional disorder” is a disorder or condition of T cells characterized by decreased responsiveness to antigenic stimulation. In a particular embodiment, a T cell dysfunctional disorder is a disorder that is specifically associated with increased kinase activity of HPK1. In another embodiment, a T cell dysfunctional disorder is one in which T cells are anergic or have decreased ability to secrete cytokines, proliferate, or execute cytolytic activity. In a specific aspect, the decreased responsiveness results in ineffective control of a pathogen or tumor expressing an immunogen. Examples of T cell dysfunctional disorders characterized by T-cell dysfunction include unresolved acute infection, chronic infection and tumor immunity.

Thus, the presently disclosed compounds can be used in treating conditions where enhanced immunogenicity is desired, such as increasing tumor immunogenicity for the treatment of cancer.

“Immunogenecity” refers to the ability of a particular substance to provoke an immune response. Tumors are immunogenic and enhancing tumor immunogenicity aids in the clearance of the tumor cells by the immune response. Viruses may also be immunogenic and enhancing/activating immunogenicity may aid in clearance of viral particles by the immune response.

“Tumor immunity” refers to the process in which tumors evade immune recognition and clearance. Thus, as a therapeutic concept, tumor immunity is “treated” when such evasion is attenuated, and the tumors are recognized and attacked by the immune system. Examples of tumor recognition include tumor binding, tumor shrinkage and tumor clearance.

In one aspect, provided herein is a method for treating of cancer in a subject in need thereof comprising administering to the subject an effective amount of a compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutically acceptable salt, prodrug, metabolite, or derivative thereof. In some embodiments, the subject has melanoma. The melanoma may be at early stage or at late stage. In some embodiments, the subject has colorectal cancer. The colorectal cancer may be at early stage or at late stage. In some embodiments, the subject has non-small cell lung cancer. The non-small cell lung cancer may be at early stage or at late stage. In some embodiments, the subject has pancreatic cancer. The pancreatic cancer may be at early stage or late state. In some embodiments, the subject has a hematological malignancy. The hematological malignancy may be at early stage or late stage. In some embodiments, the subject has ovarian cancer. The ovarian cancer may be at early stage or at late stage. In some embodiments, the subject has breast cancer. The breast cancer may be at early stage or at late stage. In some embodiments, the subject has renal cell carcinoma. The renal cell carcinoma may be at early stage or at late stage. In some embodiments, the cancer has elevated levels of T-cell infiltration.

In one aspect, provided is a method for treating viral infection in a subject in need thereof comprising administering to the subject an effective amount of a compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutically acceptable salt, prodrug, metabolite, or derivative thereof. In one aspect, provided is a method for enhancing or boosting response to a vaccine (such as a cancer vaccine or a personalized cancer vaccine (PCV)) or a CAR-T cell therapy in a subject in need thereof comprising administering to the subject an effective amount of a compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutically acceptable salt, prodrug, metabolite, or derivative thereof.

The presently disclosed compounds may be administered in any suitable manner known in the art. In some embodiments, the compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutically acceptable salt, prodrug, metabolite, or derivative thereof is administered intravenously, intramuscularly, subcutaneously, topically, orally, transdermally, intraperitoneally, intraorbitally, by implantation, by inhalation, intrathecally, intraventricularly, intratumorally, or intranasally.

In some embodiments, the HPK1 antagonist is administered continuously. In other embodiments, the HPK1 antagonist is administered intermittently. Moreover, treatment of a subject with an effective amount of a HPK1 antagonist can include a single treatment or can include a series of treatments.

It is understood that appropriate doses of the active compound depends upon a number of factors within the knowledge of the ordinarily skilled physician or veterinarian. The dose(s) of the active compound will vary, for example, depending upon the age, body weight, general health, gender, and diet of the subject, the time of administration, the route of administration, the rate of excretion, and any drug combination.

It will also be appreciated that the effective dosage of a compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutically acceptable salt, prodrug, metabolite, or derivative thereof used for treatment may increase or decrease over the course of a particular treatment. Changes in dosage may result and become apparent from the results of diagnostic assays.

In some embodiments, the HPK1 antagonist is administered to the subject at a dose of between about 0.001 μg/kg and about 1000 mg/kg, including but not limited to about 0.001 μg/kg, about 0.01 μg/kg, about 0.05 μg/kg, about 0.1 μg/kg, about 0.5 μg/kg, about 1 μg/kg, about 10 μg/kg, about 25 μg/kg, about 50 μg/kg, about 100 μg/kg, about 250 μg/kg, about 500 μg/kg, about 1 mg/kg, about 5 mg/kg, about 10 mg/kg, about 25 mg/kg, about 50 mg/kg, about 100 mg/kg, and about 200 mg/kg.

In some embodiments, provided is a method for treating a cancer in a subject in need thereof comprising administering to the subject an effective amount of a compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutically acceptable salt, prodrug, metabolite, or derivative thereof, further comprising administering an additional therapy. The additional therapy may be radiation therapy, surgery (e.g., lumpectomy and a mastectomy), chemotherapy, gene therapy, DNA therapy, viral therapy, RNA therapy, immunotherapy, bone marrow transplantation, nanotherapy, monoclonal antibody therapy, or a combination of the foregoing. The additional therapy may be in the form of adjuvant or neoadjuvant therapy. In some embodiments, the additional therapy is the administration of an anti-metastatic agent. In some embodiments, the additional therapy is the administration of side-effect limiting agents (e.g., agents intended to lessen the occurrence and/or severity of side effects of treatment, such as anti-nausea agents, etc.). In some embodiments, the additional therapy is radiation therapy. In some embodiments, the additional therapy is surgery. In some embodiments, the additional therapy is a combination of radiation therapy and surgery. In some embodiments, the additional therapy is gamma irradiation. In some embodiments, the additional therapy is therapy targeting the PI3K/AKT/mTOR pathway, HSP90 inhibitor, tubulin inhibitor, apoptosis inhibitor, and/or chemopreventative agent.

The additional therapy may be one or more of a chemotherapeutic agent. Thus, the method of treating cancer can comprise administering the presently disclosed HPK1 antagonists in conjunction with at least one chemotherapeutic agent.

As used herein, “in conjunction with” refers to administration of one treatment modality in addition to another treatment modality. As such, “in conjunction with” refers to administration of one treatment modality before, during, or after administration of the other treatment modality to the subject.

For example, the HPK1 antagonist and chemotherapeutic agent may be administered sequentially (at different times) or concurrently (at the same time). The HPK1 antagonist and chemotherapeutic agent may be administered by the same route of administration or by different routes of administration.

In certain embodiments, the HPK1 antagonist is administered in conjunction with another immunotherapy. For example, the HPK1 antagonist can be combined with a chemotherapeutic agent or biologic that targets the PD-L1/PD-1 pathway. A known inhibitory checkpoint pathway involves signaling through PD-1 receptors. The programmed-death 1 (PD-1) receptor and its ligands PD-L1 and PD-L2 are part of the same family of coregulatory molecules as CTLA-4.—See more at: http://www.onclive.com/web-exclusives/the-role-of-anti-pd-l1-immunotherapy-in-cancer/2#sthash.cGfYa1T1.dpuf. Chemotherapeutic agents or biologics that block PD-L1 binding to PD-1 and CD80 can prevent PD-L1-mediated inhibition/suppression of T-cell activation. Programmed cell death ligand-1 (PD-L1) is widely expressed on antigen-presenting cells (APC) and other immune cells. It is upregulated on tumor cells from a broad range of human cancers, and has been implicated with inhibition of antitumor T-cell immunity. PD-L1 is a cell surface protein that binds to the receptors PD-1 and CD80 on activated T cells, B cells, and other myeloid cells. PD-L1 binding to PD-1 on activated T-cells has been found to interfere with T-cell proliferation and inhibit immune responses. Overexpression of PD-L1 on cancer cells may allow these cells to avoid immune detection and elimination. High levels of PD-L1 expression on tumor cells have been associated with increased tumor aggressiveness and a poor prognosis. Chemotherapeutic agents or biologics that block PD-L1 binding to PD-1 include anti-PD-L1 antibodies, such as durvalumab, nivolumab, pidlizumab, MPDL3280A, MK-3475 and BMS-936559, among others. In some embodiments, the HPK1 antagonist is administered in conjunction with a PD-1 antagonist such as an anti-PD-1 antibody, a PD-L1 antagonist such as an anti-PD-L1 antibody, and/or a PD-L2 antagonist such as an anti-PD-L2 antibody. Examples of anti-PD-L1 antibodies include but are not limited to avelumab, atezolizumab (also known as MPDL3280A), pembrolizumab (also known as MK-3475), LY3300054 (Eli Lilly), STI-A1014 (Sorrento), KN035 (Suzhou Alphamab) and BMS-936559 (Bristol Myers Squibb). Examples of anti-PD-1 antibodies include but are not limited to nivolumab, pidlizumab, PDR001 (Novartis), REGN2810 (Regeneron), BGB-108 (BeiGene), BGB-A317 (BeiGene), JS-001 (Shanghai Junshi), STI-A1110 (Sorrento), INCSHR-1210 (Incyte), PF-06801591 (Pfizer), TSR-042 (also known as ANBO11; Tesaro/AnaptysBio), AM0001 (ARMO Biosciences), and ENUM 244C₈ (Enumeral Biomedical Holdings).

In another example, the HPK1 antagonist can be combined with a chemotherapeutic agent or biologic that targets OX40 and its ligand, OX40L, are members of the TNF superfamily. OX40 is expressed on activated CD4(+) and CD8(+) T cells as well as on a number of other lymphoid and non-lymphoid cells. Costimulatory signals from OX40 to a conventional T cell promote division and survival, augmenting the clonal expansion of effector and memory populations as they are being generated to antigen. OX40 additionally suppresses the differentiation and activity of T-regulatory cells, further amplifying this process. OX40 and OX40L also regulate cytokine production from T cells, antigen-presenting cells, natural killer cells, and natural killer T cells, and modulate cytokine receptor signaling. As one of the most prominent costimulatory molecules known to control T cells, stimulating OX40 has been shown be a target for therapeutic immunization strategies for cancer. Certain OX40 agonists include GBR 830, and those disclosed in Linch, et al., Frontiers in Oncology, v. 5, pp. 1-10 (2015), herein incorporated by reference in its entirety.

In other examples, the HPK1 antagonist can be combined with a chemotherapeutic agent or biologic that targets a CD28, OX40, GITR, CD137, CD27, CD40, ICOS, HVEM, NKG2D, MICA, 2B4, IL-2, IL-12, IFNγ, IFNα, TNFα, IL-1, CDN, HMGB1, TLR, PD-L1 axis, CTLA-4, TIM-3, BTLA, VISTA, LAG-3, B7H4, CD96, CD226, prostaglandin, VEGF, endothelin B, IDO, arginase, MICA/MICB, TIM-3, IL-10, IL-4, IL-13, TIGIT or TGFβ. In other examples, the HPK1 antagonist can be combined with an immunotherapy comprising a PD-L1 axis, CTLA-4, TIM-3, BTLA, VISTA, LAG-3, B7H4, CD96, TIGIT, CD226, prostaglandin, VEGF, endothelin B, IDO, arginase, MICA/MICB, TIM-3, IL-10, IL-4, or IL-13 antagonist. In other examples, the HPK1 antagonist can be combined with an immunotherapy comprising a CD28, OX40, GITR, CD137, CD27, CD40, ICOS, HVEM, NKG2D, MICA, 2B4, IL-2, IL-12, IFNγ, IFNα, TNFα, IL-1, CDN, HMGB1, or TLR agonist.

In another example, the HPK1 antagonist can be combined with a PCV. In another example, the HPK1 antagonist can be combined with an adoptive T cell therapy.

Provided is a method of inhibiting HPK1, said method comprising contacting HPK1 in a subject with an effective amount of a compound Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutically acceptable salt thereof; or a pharmaceutical composition comprising a compound Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutically acceptable salt thereof.

A method for enhancing an immune response in a subject in need thereof, wherein the method comprises administering to said subject an effective amount of a compound Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutically acceptable salt thereof; or a pharmaceutical composition comprising a compound Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutically acceptable salt thereof.

In some embodiments, said subject has cancer.

Also provided is a method for treating a HPK1-dependent disorder, said method comprising administering to a subject in need thereof an effective amount of a compound Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutically acceptable salt thereof; or a pharmaceutical composition comprising a compound Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), or a pharmaceutically acceptable salt thereof.

In some embodiments, said HPK1-dependent disorder is a cancer.

In some embodiments, wherein the cancer comprises at least one cancer selected from the group consisting of colorectal cancer, melanoma, non-small cell lung cancer, ovarian cancer, breast cancer, pancreatic cancer, a hematological malignancy, and a renal cell carcinoma.

In some embodiments, said method further comprises administering a chemotherapeutic agent to said subject.

In some embodiments, the invention also provides compounds of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), described herein or pharmaceutical compositions described herein for use in a method for inhibiting HPK1 as described herein, in a method for enhancing an immune response in a subject in need thereof as described herein and/or in a method for treating a HPK1-dependent disorder as described herein.

In some embodiments, the invention also provides compounds of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), described herein or pharmaceutical compositions described herein for use in a method for inhibiting HPK1 as described herein.

In some embodiments, the invention also provides compounds of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), described herein or pharmaceutical compositions described herein for use in a method for enhancing an immune response in a subject in need thereof as described herein.

In some embodiments, the invention also provides compounds of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), described herein or pharmaceutical compositions described herein for use in a method for treating a HPK1-dependent disorder as described herein.

In some embodiments, the invention also provides the use of a compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), described herein or a pharmaceutical composition described herein for the manufacture of a medicament for inhibiting HPK1, a medicament for enhancing an immune response in a subject in need thereof and/or a medicament for treating a HPK1T-dependent disorder.

In some embodiments, the invention also provides the use of a compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), described herein or a pharmaceutical composition described herein for the manufacture of a medicament for inhibiting HPK1.

In some embodiments, the invention also provides the use of a compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), described herein or a pharmaceutical composition described herein for the manufacture of a medicament for enhancing an immune response in a subject in need thereof.

In some embodiments, the invention also provides the use of a compound of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), described herein or a pharmaceutical composition described herein for the manufacture of a medicament treating a HPK1-dependent disorder.

In some embodiments, the invention also provides the use of compounds of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), described herein or pharmaceutical compositions described herein in a method for inhibiting HPK1 as described herein, in a method for enhancing an immune response in a subject in need thereof as described herein and/or in a method for treating a HPK1-dependent disorder as described herein.

In some embodiments, the invention also provides the use of compounds of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), described herein or pharmaceutical compositions described herein in a method for inhibiting HPK1 as described herein.

In some embodiments, the invention also provides the use of compounds of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), described herein or pharmaceutical compositions described herein in a method for enhancing an immune response in a subject in need thereof as described herein.

In some embodiments, the invention also provides the use of compounds of Formula (I), or variations thereof such as Formula (IA), (IB) and (IC), described herein or pharmaceutical compositions described herein in a method for treating a HPK1-dependent disorder as described herein.

In some embodiments, the treatment results in a sustained response in the subject after cessation of the treatment. “Sustained response” refers to the sustained effect on reducing tumor growth after cessation of a treatment. For example, the tumor size may remain the same or smaller as compared to the size at the beginning of the administration phase. In some embodiments, the sustained response has a duration at least the same as the treatment duration, at least 1.5×, 2.0×, 2.5×, or 3.0× length of the treatment duration.

The treatment methods disclosed herein may result in a partial or complete response. As used herein, “complete response” or “CR” refers to disappearance of all target lesions; “partial response” or “PR” refers to at least a 30% decrease in the sum of the longest diameters (SLD) of target lesions, taking as reference the baseline SLD; and “stable disease” or “SD” refers to neither sufficient shrinkage of target lesions to qualify for PR, nor sufficient increase to qualify for PD, taking as reference the smallest SLD since the treatment started. As used herein, “overall response rate” (ORR) refers to the sum of complete response (CR) rate and partial response (PR) rate.

The treatment methods disclosed herein can lead to an increase in progression free survival and overall survival of the subject administered the HPK1 antagonist. As used herein, “progression free survival” (PFS) refers to the length of time during and after treatment during which the disease being treated (e.g., cancer) does not get worse. Progression-free survival may include the amount of time patients have experienced a complete response or a partial response, as well as the amount of time patients have experienced stable disease.

As used herein, “overall survival” refers to the percentage of subjects in a group who are likely to be alive after a particular duration of time.

In some embodiments, the subject that is administered a HPK1 antagonist is a mammal, such as domesticated animals (e.g., cows, sheep, cats, dogs, and horses), primates (e.g., humans and non-human primates such as monkeys), rabbits, and rodents (e.g., mice and rats). In some embodiments, the subject treated is a human.

The subject in need of treatment for cancer may be a person demonstrating symptoms of cancer, one that has been diagnosed with cancer, a subject that is in remission from cancer, or a subject having an increased risk for developing cancer (e.g., a genetic predisposition, certain dietary or environmental exposures).

In any of the described methods, in one aspect the subject is a human, such as a human in need of the method. The subject may be a human who has been diagnosed with or is suspected of having an HPK1-dependent disorder such as cancer. The individual may be a human who does not have detectable disease but who has one or more risk factors for developing a cancer.

Further provided are kits for carrying out the methods detailed herein, which comprises one or more compounds described herein or a pharmaceutical composition comprising a compound described herein. The kits may employ any of the compounds disclosed herein. In one variation, the kit employs a compound described herein or a pharmaceutically acceptable salt thereof. The kits may be used for any one or more of the uses described herein, and, accordingly, may contain instructions for use in the treatment of an HPK1-dependent disorder such as cancer. In some embodiments, the kit contains instructions for use in the treatment of a cancer.

Kits generally comprise suitable packaging. The kits may comprise one or more containers comprising any compound described herein. Each component (if there is more than one component) can be packaged in separate containers or some components can be combined in one container where cross-reactivity and shelf life permit. One or more components of a kit may be sterile and/or may be contained within sterile packaging.

The kits may be in unit dosage forms, bulk packages (e.g., multi-dose packages) or sub-unit doses. For example, kits may be provided that contain sufficient dosages of a compound as disclosed herein (e.g., a therapeutically effective amount) and/or a second pharmaceutically active compound useful for an HPK1-dependent disorder (e.g., cancer) to provide effective treatment of an individual for an extended period, such as any of a week, 2 weeks, 3 weeks, 4 weeks, 6 weeks, 8 weeks, 3 months, 4 months, 5 months, 7 months, 8 months, 9 months, or more. Kits may also include multiple unit doses of the compounds and instructions for use and be packaged in quantities sufficient for storage and use in pharmacies (e.g., hospital pharmacies and compounding pharmacies).

The kits may optionally include a set of instructions, generally written instructions, although electronic storage media (e.g., magnetic diskette or optical disk) containing instructions are also acceptable, relating to the use of component(s) of the methods of the present invention. The instructions included with the kit generally include information as to the components and their administration to a subject.

The following examples are offered by way of illustration and not by way of limitation.

EXAMPLES LC/MS Methods

Method K: Experiments were performed on a Shimadzu 20AD HPLC with Shimadzu LCMS2020 mass spectrometer using ESI as ionization source, a Shim-Pack XR-ODS C_(18 2.2) um, 3.0×50 mm column, and a 1.2 ml/minute flow rate. The solvent system was a gradient starting with 95% water with 0.05% TFA (solvent A) and 5% acetonitrile with 0.05% TFA (solvent B), ramping up to 95% solvent B over 2.0 minutes. The final solvent system was held constant for a further 0.7 minutes.

Method O: Experiment was performed on a Waters Acquity UPLC with Waters LCT Premier XE mass spectrometer using ESI ionization. The LC separation was using an Acquity UPLC BEH C18, 1.7 mm, 2.1×50 mm column and a 0.6 ml/min flow rate. MPA (mobile phase A) was water with 0.05% TFA and MPB (mobile phase B) was acetonitrile with 0.05% TFA. The gradient consisted with 2-98% MPB over 5 min and hold 98% B for 0.5 min following equilibration for 0.5 min. LC column temperature is 40 C. UV data was collected at 220 nm and 254 nm and mass spec full scan was applied to all experiments.

SYNTHETIC EXAMPLES Example 1 tert-butyl (6-bromo-2,7-naphthyridin-3-yl)carbamate

Step 1: 6-bromo-4-iodonicotinic acid

A dry three neck-round bottom flask (10 L) contained TMP (2,2,6,6-tertramethylpiperidine, fresh distilled, 629 g, 4.46 mol) and dry THF (3 L) under N₂ was cooled to below −55° C. n-BuLi in hexane solution (2.5 M, 1783 mL, 4.46 mol) was added dropwise to the cooled solution over 2 hrs. The suspension was stirred for 30 mins at below −40° C. 6-Bromonicotinic acid (white powder, dried under vacuum before use) (300 g, 1.485 mol) was added quickly in four portions and the suspension was stirred at −20° C. for 2 hrs, over which time the reaction turned from orange to brown. The reaction mixture was cooled to below −50° C. and quickly transferred into a pre-cooled solution of I₂ (1130.8 g, 4.455 mol) in dry THF (3 L) under N₂. The resulting mixture was allowed to warm to room temperature with stirring overnight. The reaction solvent was removed under vacuum and the residue was suspended in water (3000 mL), then washed with DCM (9 L×2). The aqueous layer was acidified by addition of concentrated HCl to pH=2 and the precipitate was collected by filtration, washed with water (600 mL) and petroleum ether (300 mL), then dried under vacuum at 60° C. to afford the desired product as a tan solid (340 g, 70%).

Step 2: (6-bromo-4-iodopyridin-3-yl)methanol

To a solution of 6-bromo-4-iodonicotinic acid (320 g, 0.976 mol) in 4800 mL anhydrous THF at 0° C. under N₂ was added BH₃.THF (3000 mL, 3 mol) dropwise. The reaction mixture was allowed to warm to room temperature and stirred for 14 hrs, then poured slowly into ice water. The pH of the solution was adjusted to 8 by addition of aqueous K₂CO₃. The resulting mixture was extracted with ethyl acetate (4000 mL×3), the organic layers were washed with brine, dried over anhydrous sodium sulfate, filtered, and concentrated. The resulting residue was purified by silica gel chromatography to afford the titled compound as a white solid (164 g, 54%).

Step 3: 6-bromo-4-iodonicotinaldehyde

A mixture of 6-bromo-4-iodopyridin-3-yl)methanol (31.4 g, 100 mmol) and trichloroisocyanuric acid (24.4 g, 105 mmol) in DCM (900 mL) was cooled to 0° C. and then TEMPO (156.2 mg, 1 mmol) was added. The mixture was stirred for 10 min at 0° C., then filtered. The filtrate was washed with 5% Na₂CO₃, then brine. The organic layer was collected, dried over anhydrous sodium sulfate, filtered and concentrated to give the title compound as a light yellow solid (24 g. 77%).

Step 4: 1-(6-bromo-4-iodopyridin-3-yl)-N-(tert-butyl)methanimine

To a mixture of 6-bromo-4-iodonicotinaldehyde (125.01 g, 400.8 mmol) and H₂O (1000 mL) was added 2-ethylpropan-2-amine (117.35 g, 1603.2 mmol). The mixture was stirred at 25° C. for 16 hrs, then extracted with ethyl acetate (1500 mL×2). The combined organic layers were dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated to afford the crude title compound as a light yellow solid (144.9 g, 98%) which was used directly in the next step without further purification.

Step 5: (6-bromo-2,7-naphthyridin-3-yl)methanol

To a 1000 mL reactor was added CH₃CN (700 mL), 1-(6-bromo-4-iodopyridin-3-yl)-N-(tert-butyl)methanimine (144.9 g, 0.395 mol), tert-butyldimethyl(prop-2-ynyloxyl)silane (73.84 g, 0.434 mol), and NiCl₂(DPPP) (10.71 g, 19.75 mmol), and Zn power (4.39 g, 67.13 mmol). The reaction mixture was stirred under reflux for 30 min, then cooled to 10° C. and filtered. Water (300 mL) was added to the filtrate, and this mixture was extracted with ethyl acetate (600 mL×3). The organic layers were combined, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The resulting residue was purified via silica gel chromatography (10% ethyl acetate in petroleum ether) to afford a pink solid (46 g, 33%). The solid was dissolved in ethanol (1000 mL) and treated with dry HCl gas. The resulting mixture was stirred at 25° C. for 12 hrs. TLC showed the starting material was completely consumed and the reaction mixture was treated with saturated aqueous NaHCO₃ solution to pH>7. The aqueous solution was extracted with ethyl acetate (500 mL×4) and the combined organic layers was washed with brine (400 mL×2), dried with sodium sulfate, and filtered. The filtrate was concentrated to afford the title compound as a white solid (31.5 g, 33%) which was used directly in the next step without further purification.

Step 6: 6-bromo-2,7-naphthyridine-3-carboxylic acid

IBX (55.36 g, 197.70 mmol) was added to a solution of 6-bromo-2,7-naphthyridin-3-yl)methanol (31.5 g, 131.8 mmol) in DCM (1050 mL)/DMSO (260 mL) at 0° C. The reaction mixture was stirred at room temperature for 9 hrs, then diluted with DCM (500 mL). This solution was washed with aqueous 10% K₂CO₃ (500 mL×2) and brine (500 mL). The organic layer was dried with sodium sulfate and filtered. The filtrate was concentrated to afford crude 6-bromo-2,7-naphthyridine-3-carbaldehyde (30.8 g) as a yellow solid. The crude 6-bromo-2,7-naphthyridine-3-carbaldehyde (30.8 g, 131.8 mmol) was dissolved in 1,4-dioxane (800 mL) and water (350 mL), followed by the sequential addition of sulfamic acid (15.34 g, 158.2 mmol) and a solution of sodium chlorite (14.3 g, 158.2 mmol) in water (140 mL) dropwise. The reaction mixture was stirred for 3 hrs at room temperature. The reaction was diluted with water (1200 mL) and filtered. The filter cake was washed with water (2×250 mL) and acetone (150 mL) and dried under reduced pressure to give crude 6-bromo-2,7-naphthyridine-3-carboxylic acid (24.1 g, 72% for 2 steps) as a light yellow solid which was used directly in the next step without further purification.

Step 7: tert-butyl (6-bromo-2,7-naphthyridin-3-yl)carbamate

To a solution compound 6-bromo-2,7-naphthyridine-3-carboxylic acid (24.1 g, 95.26 mmol), tert-butyl alcohol (141 g, 1.905 mol) and N, N-diisopropylethylamine (15.98 g, 123.84 mmol) in toluene (1000 mL) under N₂ was added a solution of diphenylphosphoryl azide (34.06 g, 123.84 mmol) in 100 mL of toluene dropwise over 50 min at 90° C. The reaction mixture was stirred at reflux for 2 hrs until the starting material was consumed. Upon cooling to room temperature, the reaction was quenched slowly with methanol (2000 mL). The resulting mixture was stirred for 20 min and filtered. The filter cake was washed with methanol (200 mL), dried under vacuum at 40° C. to afford tert-butyl (6-bromo-2,7-naphthyridin-3-yl)carbamate as light yellow needles (18.5 g, 60%).

Example 2 tert-butyl N-(6,8-dichloro-2,7-naphthyridin-3-yl)carbamate

Step 1: 2,6-dichloro-4-iodonicotinic acid

To a solution of 2,6-dichloro-3-iodo-pyridine (13.69 g, 50 mmol) in dry THF (150 mL) was added dropwise LDA (2.0 M in THF, 27.5 mL, 55 mmol) at −78° C. under N₂. The reaction mixture was stirred at −78° C. for 2 hrs, then CO₂ was bubbled through for 5 minutes and the solution was warmed to room temperature and stirred for 2 hrs. The reaction was quenched with conc. HCl, diluted with water, and extracted three times with dichloromethane. The combined organic layers were dried over Na₂SO₄, filtered and concentrated to give 2,6-dichloro-4-iodo-pyridine-3-carboxylic acid (8.1 g, 51% yield) as a light yellow solid. LCMS (ESI) [M+H]⁺=317.8.

Step 2: (2,6-dichloro-4-iodopyridin-3-yl)methanol

A mixture of 2,6-dichloro-4-iodo-pyridine-3-carboxylic acid (6 g, 18.87 mmol) in THF (10 mL) was cooled to 0° C. BH₃.THF (1 M in THF, 94 mL, 94 mmol) was added slowly and then the reaction mixture was stirred at 85° C. for 16 hrs. The mixture was cooled to room temperature then poured into ice water. The pH was adjusted to 8 with aqueous K₂CO₃, then this solution was extracted with ethyl acetate (30 mL×2). The combined organic layers were dried over Na₂SO₄, filtered and concentrated. The crude product was purified by flash chromatography (petroleum ether/ethyl acetate=10/1) to give (2,6-dichloro-4-iodo-3-pyridyl)methanol (4 g, 69% yield) as a yellow solid. LCMS (ESI) [M+H]⁺=303.9.

Step 3: 2,6-dichloro-4-iodonicotinaldehyde

To a solution of (2,6-dichloro-4-iodo-3-pyridyl)methanol (2.5 g, 8.23 mmol) in dichloromethane (100 mL) was added PCC (5 g, 23.26 mmol). The reaction mixture was stirred at 25° C. for 1 hour. The reaction mixture was filtered through a silica gel column and concentrated. The residue was purified by flash chromatography (petroleum ether/ethyl acetate=20/1) to give 2,6-dichloro-4-iodo-pyridine-3-carbaldehyde (1.6 g, 64% yield) as a yellow solid. ¹H NMR (400 MHz, CDCl₃) δ 10.17 (s, 1H), 7.99 (s, 1H).

Step 4: (E)-N-tert-butyl-1-(2,6-dichloro-4-iodopyridin-3-yl)methanimine

A mixture of 2,6-dichloro-4-iodo-pyridine-3-carbaldehyde (6.2 g, 20 mmol) and tert-butylamine (7.51 g, 103 mmol) in water (50 mL) was stirred at room temperature for 18 hrs. The reaction mixture was extracted with ethyl acetate (3×), then the combined organic layers were dried over Na₂SO₄, filtered, and concentrated to give N-tert-butyl-1-(2,6-dichloro-4-iodo-3-pyridyl) methanimine (7.2 g, 96% yield) as a white solid. LCMS (ESI) [M+H]+=356.9.

Step 5: 6-((tert-butyldimethylsilyloxy)methyl)-1,3-dichloro-2,7-naphthyridine

A mixture of N-tert-butyl-1-(2,6-dichloro-4-iodo-3-pyridyl)methanimine (7.2 g, 20 mmol), tert-butyldimethyl(prop-2-ynyloxy)silane (3.78 g, 22 mmol), NiCl₂(DPPP) (546 mg, 1.01 mmol), Zn (196 mg, 3.03 mmol) in acetonitrile (40 mL) was heated to 85° C. for 18 hrs under N₂. The reaction mixture was filtered and the filtrate was diluted with ethyl acetate, washed with water, dried over Na₂SO₄, filtered and concentrated. The crude product was purified by flash chromatography (petroleum ether/ethyl acetate=15/1) to give tert-butyl-[(6,8-dichloro-2,7-naphthyridin-3-yl)methoxy]-dimethyl-silane (4 g, 44% yield) as a light yellow solid. LCMS (ESI) [M+H]+=343.0.

Step 6: (6,8-dichloro-2,7-naphthyridin-3-yl)methanol

A solution of tert-butyl-[(6,8-dichloro-2,7-naphthyridin-3-yl)methoxy]-dimethyl-silane (4 g, 11.65 mmol) in HCl in ethanol (20 mL, 40 mmol) was stirred at 25° C. for 4 hrs. The reaction mixture was filtered and the solid was collected, dissolved in aqueous NaHCO₃, and extracted with dichloromethane. The combined organic layers were dried over Na₂SO₄, filtered, and concentrated to give (6,8-dichloro-2,7-naphthyridin-3-yl)methanol (2.5 g, 81% yield) as a yellow solid. LCMS (ESI) [M+H]+=343.0.

Step 7: 6,8-dichloro-2,7-naphthyridine-3-carbaldehyde

To a solution of (6,8-dichloro-2,7-naphthyridin-3-yl)methanol (2.8 g, 12 mmol) in dichloromethane (100 mL) and DMSO (25 mL) was added IBX (5.13 g, 18 mmol) at 0° C. The reaction solution was stirred at room temperature for 18 hrs. The reaction mixture was diluted with dichloromethane, washed with 10% aqueous K₂CO₃, then brine. The organic layer was collected, dried over MgSO₄, filtered, and concentrated to give 6,8-dichloro-2,7-naphthyridine-3-carbaldehyde (2.2 g, 78% yield) as a white solid. LCMS (ESI) [M+H]⁺=226.9.

Step 8: 6,8-dichloro-2,7-naphthyridine-3-carboxylic acid

To a solution of 6,8-dichloro-2,7-naphthyridine-3-carbaldehyde (2.2 g, 9.69 mmol) in 1,4-dioxane (80 mL) and water (30 mL) was added NH₂SO₃H (1.13 g, 11.63 mmol) and NaClO₂ (1.05 g, 11.63 mmol) at room temperature. The reaction solution was stirred at room temperature for 18 hrs. The resulting mixture was diluted with water to produce a precipitate which was collected by filtration, washed with water and acetone to give 6,8-dichloro-2,7-naphthyridine-3-carboxylic acid (2.2 g, 74% yield) as a white solid. LCMS (ESI) [M+H]⁺=242.9.

Step 9: tert-butyl N-(6,8-dichloro-2,7-naphthyridin-3-yl)carbamate

To a solution of 6,8-dichloro-2,7-naphthyridine-3-carboxylic acid (230 mg, 0.94 mmol), t-BuOH (1.4 g, 18.93 mmol) and DIPEA (158 mg, 1.23 mmol) in toluene (20 mL) was added a solution of DPPA (338 mg, 1.23 mmol) in toluene (2 mL) at 90° C. under N₂. The reaction solution was stirred at reflux for 2 hrs. Upon cooling to room temperature, methanol (40 mL) was added and the resulting solution was stirred at room temperature for 20 minutes. The solvent was removed under vacuum, then the residue was washed with methanol and dried to give tert-butyl N-(6,8-dichloro-2,7-naphthyridin-3-yl)carbamate (250 mg, 75% yield) as a white solid. LCMS (ESI) [M−55]⁺=257.9. ¹H NMR (400 MHz, DMSO-d₆) δ 10.56 (s, 1H), 9.37 (s, 1H), 8.23 (s, 1H), 8.10 (s, 1H), 1.52 (s, 9H).

Example 3 6,8-dichloro-2,7-naphthyridin-3-amine

To a vial was added tert-butyl N-(6,8-dichloro-2,7-naphthyridin-3-yl)carbamate (1.05 g, 3.34 mmol), HCl in 1,4-dioxane (10 mL, 4 N, 40 mmol), and dichloromethane (5 mL). The mixture was stirred at 40° C. for 4 hrs, then concentrated and dried under vacuum to give 6,8-dichloro-2,7-naphthyridin-3-amine hydrochloride (823 mg, 96% yield) as a yellow solid. LCMS (ESI) [M+H]⁺=214.1.

Example 4 tert-butyl N-[6-(4-methyl-3-pyridyl)-2,7-naphthyridin-3-yl]carbamate

A mixture of tert-butyl (6-bromo-2,7-naphthyridin-3-yl)carbamate (0.46 g, 1.37 mmol), 4-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (0.78 g, 3.57 mmol), Pd(dppf)Cl₂ (182 mg, 0.25 mmol) in acetonitrile (10 mL) and 1M aqueous K₂CO₃ solution (10 mL) was stirred at 110° C. for 30 min. The reaction was filtered and the filtrate was extracted with EtOAc, dried over sodium sulfate, filtered, and concentrated. The resulting residue was purified by silica gel flash chromatography (0-20% MeOH in DCM) to give tert-butyl N-[6-(4-methyl-3-pyridyl)-2,7-naphthyridin-3-yl]carbamate (0.46 g, 55%).

Example 101 2′-((6-(5-amino-4-methylpyridin-3-yl)-8-methyl-2,7-naphthyridin-3-yl)amino)-6′-methyl-5′,6′-dihydrospiro[cyclopropane-1,4′-pyrazolo[1,5-d][1,4]diazepin]-7′(8′H)-one (Compound 101)

Step 1: 6-Chloro-8-methyl-2,7-naphthyridin-3-amine

A mixture of 6,8-dichloro-2,7-naphthyridin-3-amine (500 mg, 2.34 mmol), trimethylboroxine (1.47 g, 11.68 mmol), [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (342 mg, 0.47 mmol), and sodium carbonate (1.24 g, 11.68 mmol) in 1,4-dioxane (20 mL) and water (3.0 mL) was stirred at 110° C. for 3 hrs. Upon cooling to room temperature, the solution was filtered and the filtrate was concentrated under vacuum then purified by reversed phase HPLC with 0.5% NH₄HCO₃ in H₂O/MeOH (40%) to afford 6-chloro-8-methyl-2,7-naphthyridin-3-amine (120 mg, 0.62 mmol) as a yellow solid. LCMS (ESI) [M+H]⁺=194.0.

Step 2: Tert-butyl N-[5-(6-amino-1-methyl-2,7-naphthyridin-3-yl)-4-methyl-3-pyridyl]-N-tert-butoxycarbonyl-carbamate

A mixture of 6-chloro-8-methyl-2,7-naphthyridin-3-amine (150 mg, 0.77 mmol), tert-butyl N-tert-butoxycarbonyl-N-[4-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3-pyridyl]carbamate (673 mg, 1.55 mmol), [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (85 mg, 0.12 mmol), sodium carbonate (246 mg, 2.32 mmol) in 1,4-dioxane (15 mL) and water (2.0 mL) was stirred at 90° C. for 2 hrs. Upon cooling to room temperature, the solution was filtered and the filtrate was concentrated under vacuum. The resulting residue was purified by flash chromatography on silica gel eluted with dichloromethane/methanol (20/1) to afford tert-butyl N-[5-(6-amino-1-methyl-2,7-naphthyridin-3-yl)-4-methyl-3-pyridyl]-N-tert-butoxycarbonyl-carbamate (100 mg, 0.22 mmol) as a light yellow solid. LCMS (ESI) [M+H]⁺=466.3.

Step 3: Tert-butyl N-tert-butoxycarbonyl-N-[4-methyl-5-[1-methyl-6-[(6-methyl-7-oxo-spiro[5,8-dihydropyrazolo[1,5-d][1,4]diazepine-4,1′-cyclopropane]-2-yl)amino]-2,7-naphthyridin-3-yl]-3-pyridyl]carbamate

A mixture of tert-butyl N-[5-(6-amino-1-methyl-2,7-naphthyridin-3-yl)-4-methyl-3-pyridyl]-N-tert-butoxycarbonyl-carbamate (100 mg, 0.21 mmol), 2-bromo-6-methyl-spiro[5,8-dihydropyrazolo[1,5-d][1,4]diazepine-4,1′-cyclopropane]-7-one (58 mg, 0.21 mmol), t-BuBrettPhos Pd G3 (74 mg, 0.09 mmol), t-BuBrettPhos (52 mg, 0.11 mmol), and cesium carbonate (210 mg, 0.64 mmol) in 1,4-dioxane (10 mL) was stirred at 130° C. for 3 hrs. Upon cooling to room temperature, the mixture was filtered and the filtrate was concentrated under vacuum to afford tert-butyl N-tert-butoxycarbonyl-N-[4-methyl-5-[1-methyl-6-[(6-methyl-7-oxo-spiro[5,8-dihydropyrazolo[1,5-d][1,4]diazepine-4,1′-cyclopropane]-2-yl)amino]-2,7-naphthyridin-3-yl]-3-pyridyl]carbamate (100 mg, crude) as a brown solid. LCMS (ESI) [M+H]⁺=655.5.

Step 4: 2-[[6-(5-Amino-4-methyl-3-pyridyl)-8-methyl-2,7-naphthyridin-3-yl]amino]-6-methyl-spiro[5,8-dihydropyrazolo[1,5-d][1,4]diazepine-4,1′-cyclopropane]-7-one

A solution of tert-butyl N-tert-butoxycarbonyl-N-[4-methyl-5-[1-methyl-6-[(6-methyl-7-oxo-spiro[5,8-dihydropyrazolo[1,5-d][1,4]diazepine-4,1′-cyclopropane]-2-yl)amino]-2,7-naphthyridin-3-yl]-3-pyridyl]carbamate (100 mg, 0.15 mmol) in dichloromethane (2 mL) and trifluoroacetic acid (2 mL) was stirred at 20° C. for 2 hrs. The mixture was concentrated under vacuum. The reaction mixture was adjusted to pH 10 by adding 7 M of ammonia in methanol. The crude product was purified by Prep-HPLC (C18; 0.5% NH₄HCO₃ in water:MeOH=5%-65% in 15 min) to afford 2-[[6-(5-amino-4-methyl-3-pyridyl)-8-methyl-2,7-naphthyridin-3-yl]amino]-6-methyl-spiro[5,8-dihydropyrazolo[1,5-d][1,4]diazepine-4,1′-cyclopropane]-7-one (16.6 mg, 0.037 mmol) as a yellow solid. LCMS (ESI) [M+H]⁺=455.3; ¹H NMR (400 MHz, DMSO-d₆) δ 9.59 (s, 1H), 9.30 (s, 1H), 7.98 (s, 1H), 7.81 (s, 1H), 7.71 (s, 1H), 7.48 (s, 1H), 5.69 (s, 1H), 5.18 (s, 2H), 5.10 (s, 2H), 3.74 (s, 2H), 2.99 (s, 3H), 2.88 (s, 3H), 2.06 (s, 3H), 1.20-1.17 (m, 2H), 0.96-0.94 (m, 2H). Analytical HPLC retention time 1.678 min, Method K.

Example 102 Example 26: 2-((6-(5-amino-4-methylpyridin-3-yl)-2,7-naphthyridin-3-yl)amino)-6-(2,2-difluoroethyl)-5,6-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-7(8H)-one (Compound 102)

Step 1: 2-Bromo-6-(2,2-difluoroethyl)-5,8-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-7-one

To a solution of 2-bromo-4,5,6,8-tetrahydropyrazolo[1,5-d][1,4]diazepin-7-one (500 mg, 2.17 mmol) in N,N-dimethylformamide (30 mL) was added sodium hydride (157 mg, 3.92 mmol, 60%) at 0° C. The resulting mixture was stirred at 0° C. for 0.5 hours. Then 1,1-difluoro-2-iodoethane (2.09 g, 10.87 mmol) in N,N-dimethylformamide (5 mL) was added at 0° C. and the resulting solution was stirred at 20° C. for 3 hrs. The reaction was quenched with water (0.5 ml) and the organic residue was purified by reversed-phase column chromatography (0.5% NH₄HCO₃ in water/CH₃CN=5%-50% in 25 min) to afford 2-bromo-6-(2,2-difluoroethyl)-5,8-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-7-one (290 mg, 0.99 mmol) as a light yellow solid. LCMS (ESI) [M+H]⁺=294.1.

Step 2: Tert-butyl N-tert-butoxycarbonyl-N-[5-[6-[[6-(2,2-difluoroethyl)-7-oxo-5,8-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-2-yl]amino]-2,7-naphthyridin-3-yl]-4-methyl-3-pyridyl]carbamate

A mixture of 2-bromo-6-(2,2-difluoroethyl)-5,8-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-7-one (127 mg, 0.43 mmol), tert-butyl N-[5-(6-amino-2,7-naphthyridin-3-yl)-4-methyl-3-pyridyl]-N-tert-butoxycarbonyl-carbamate (130 mg, 0.29 mmol), t-BuBrettPhos Pd G3 (246 mg, 0.29 mmol), t-BuBrettPhos (209 mg, 0.43 mmol), and cesium carbonate (282 mg, 0.86 mmol) in 1,4-dioxane (15 mL) was stirred at 130° C. for 2 hrs. Upon cooling to room temperature the mixture was filtered and the filtrate was concentrated under vacuum to afford tert-butyl N-tert-butoxycarbonyl-N-[5-[6-[[6-(2,2-difluoroethyl)-7-oxo-5,8-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-2-yl]amino]-2,7-naphthyridin-3-yl]-4-methyl-3-pyridyl]carbamate (120 mg, crude) as brown oil. LCMS (ESI) [M+H]⁺=665.2.

Step 3: 2-[[6-(5-Amino-4-methyl-3-pyridyl)-2,7-naphthyridin-3-yl]amino]-6-(2,2-difluoroethyl)-5,8-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-7-one

A solution of tert-butyl N-tert-butoxycarbonyl-N-[5-[6-[[6-(2,2-difluoroethyl)-7-oxo-5,8-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-2-yl]amino]-2,7-naphthyridin-3-yl]-4-methyl-3-pyridyl]carbamate (80 mg, 0.12 mmol) and trifluoroacetic acid (5.0 mL) in dichloromethane (2 mL) was stirred at 20° C. for 1 h. The reaction was concentrated under vacuum. The reaction mixture was adjusted to pH=10 by addition of 7M of ammonia in methanol. After concentrated under vacuum the residue was purified by Prep-HPLC (XBridge Prep C18 OBD 19*15 mm 5 um; 10 mmol NH₄HCO₃ in water: CH₃CN=18%-45% in 7 min) to afford 2-[[6-(5-amino-4-methyl-3-pyridyl)-2,7-naphthyridin-3-yl]amino]-6-(2,2-difluoroethyl)-5,8-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-7-one (15 mg, 0.03 mmol) as a light yellow solid. LCMS (ESI) [M+H]⁺=465.2; ¹H NMR (400 MHz, DMSO-d₆) δ 9.71 (s, 1H), 9.24 (s, 1H), 9.19 (s, 1H), 7.99 (s, 1H), 7.83 (s, 1H), 7.79 (s, 1H), 7.65 (s, 1H), 6.38-5.95 (m, 2H), 5.21 (s, 2H), 5.09 (s, 2H), 3.96-3.85 (m, 4H), 3.09-3.08 (m, 2H), 2.07 (s, 3H). Analytical HPLC retention time 1.718 min, Method K.

Example 103 6-isopropyl-2-((6-(8-methyl-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazin-7-yl)-2,7-naphthyridin-3-yl)amino)-5,6-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-7(8H)-one (Compound 103)

Step 1: tert-butyl7-(6-amino-2,7-naphthyridin-3-yl)-8-methyl-2,3-dihydropyrido[2,3-b][1,4]oxazine-1-carboxylate

A solution of 6-chloro-2,7-naphthyridin-3-amine (240 mg, 1.34 mmol), tert-butyl 7-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,3-dihydropyrido[2,3-b][1,4]oxazine-1-carboxylate (726.03 mg, 2.0 mmol), [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (195.54 mg, 0.27 mmol) and sodium carbonate (424.88 mg, 4.01 mmol) in 1,4-dioxane (1 mL) and water (0.20 mL) was stirred at 90° C. for 2 hrs. The resulting solution was cooled to room temperature and then concentrated under vacuum. The residue was purified by flash chromatography on silica gel, eluting with dichloromethane/methanol (10/1) to afford tert-butyl7-(6-amino-2,7-naphthyridin-3-yl)-8-methyl-2,3-dihydropyrido[2,3-b][1,4]oxazine-1-carboxylate (220 mg, 0.56 mmol) as a yellow solid. LCMS (ESI) [M+H]⁺=394.

Step 2: tert-butyl 7-[6-[(6-isopropyl-7-oxo-5,8-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-2-yl)amino]-2,7-naphthyridin-3-yl]-8-methyl-2,3-dihydropyrido[2,3-b][1,4]oxazine-1-carboxylate

A solution of 2-bromo-6-isopropyl-5,8-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-7-one (155.63 mg, 0.57 mmol), tert-butyl 7-(6-amino-2,7-naphthyridin-3-yl)-8-methyl-2,3-dihydropyrido[2,3-b][1,4]oxazine-1-carboxylate (150 mg, 0.38 mmol), tris(dibenzylideneacetone)dipalladium-chloroform adduct (78 mg, 0.08 mmol), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (88.24 mg, 0.15 mmol), and cesium carbonate (372.66 mg, 1.14 mmol) in 1,4-dioxane (1.5 mL) was stirred at 100° C. for 2 hrs. The resulting solution was cooled to room temperature and then concentrated under vacuum. The residue was purified by flash chromatography on silica gel, eluting with dichloromethane/methanol (10/1) to afford tert-butyl 7-[6-[(6-isopropyl-7-oxo-5,8-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-2-yl)amino]-2,7-naphthyridin-3-yl]-8-methyl-2,3-dihydropyrido[2,3-b][1,4]oxazine-1-carboxylate (90 mg, 0.15 mmol) as a yellow solid. LCMS (ESI) [M+H]=585.

Step 3: 6-isopropyl-2-[[6-(8-methyl-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazin-7-yl)-2,7-naphthyridin-3-yl]amino]-5,8-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-7-one

To a solution of tert-butyl 7-[6-[(6-isopropyl-7-oxo-5,8-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-2-yl)amino]-2,7-naphthyridin-3-yl]-8-methyl-2,3-dihydropyrido[2,3-b][1,4]oxazine-1-carboxylate (90 mg, 0.15 mmol) in dichloromethane (5 mL) was added trifluoroacetic acid (1.0 mL) and the resulting solution was stirred at 25° C. for 1 h. The reaction solution was concentrated under vacuum. The residue was purified by Prep-HPLC (XBridge Prep C18 OBD, 19×150 mm 5 um; water (10 mmol/L NH₄HCO₃): CH₃CN=12%-42% in 7 min) to afford 6-isopropyl-2-[[6-(8-methyl-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazin-7-yl)-2,7-naphthyridin-3-yl]amino]-5,8-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-7-one (24.1 mg, 0.05 mmol) as a yellow solid. LCMS (ESI) [M+H]⁺=485; ¹H NMR (400 MHz, DMSO-d₆) δ 9.66 (s, 1H), 9.22 (s, 1H), 9.16 (s, 1H), 7.76 (s, 1H), 7.61 (s, 1H), 7.53 (s, 1H), 6.05 (s, 1H), 5.63 (s, 1H), 5.01 (s, 2H), 4.61-4.58 (m, 1H), 4.30-4.28 (m, 2H), 3.81-3.78 (m, 2H), 3.37-3.36 (m, 2H), 3.02-3.00 (m, 2H), 2.11 (s, 3H), 1.13 (d, J=6.8 Hz, 6H). Analytical HPLC retention time 1.782 min, Method K.

Example 104 2-((6-(5-amino-4-methylpyridin-3-yl)-2,7-naphthyridin-3-yl)amino)-6-isopropyl-5,6-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-7(8H)-one (Compound 104)

Step 1: 6-chloro-2,7-naphthyridin-3-amine

A solution of (6,8-dichloro-2,7-naphthyridin-3-yl)ammonium chloride (1.0 g, 4.0 mmol), sodium borohydride (453 mg, 12 mmol), TEMED (3.6 mL, 24 mmol), and [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (326 mg, 0.40 mmol) in tetrahydrofuran (20 mL) was stirred at 25° C. for 2.5 hrs. The reaction mixture was diluted with water, then extracted with dichloromethane (3×). The combined organic layers were dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum. The resulting residue was purified by flash chromatography on silica gel eluting with dichloromethane/methanol (10/1) to afford 6-chloro-2,7-naphthyridin-3-amine (480 mg, 2.4 mmol) as a yellow solid. LCMS (ESI) [M+H]⁺=180.

Step 2: tert-butyl N-[5-(6-amino-2,7-naphthyridin-3-yl)-4-methyl-3-pyridyl]-N-tert-butoxycarbonyl-carbamate

A solution of 6-chloro-2,7-naphthyridin-3-amine (200 mg, 1.11 mmol), tert-butyl N-tert-butoxycarbonyl-N-[4-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3-pyridyl]carbamate (725.46 mg, 1.67 mmol), sodium carbonate (354.1 mg, 3.34 mmol), and tetrakis(triphenylphosphine)palladium(0) (128.67 mg, 0.11 mmol) in 1,4-dioxane (2 mL) and water (0.40 mL) was stirred at 90° C. for 2 hrs. The resulting solution was concentrated under vacuum and the residue was purified by flash chromatography on silica gel, eluting with dichloromethane/methanol (10/1) to afford tert-butyl N-[5-(6-amino-2,7-naphthyridin-3-yl)-4-methyl-3-pyridyl]-N-tert-butoxycarbonyl-carbamate (220 mg, 0.49 mmol) as an off-white solid. LCMS (ESI) [M+H]⁺=452.

Step 3: [tert-butoxycarbonyl-[5-[6-[(6-isopropyl-7-oxo-5,8-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-2-yl)amino]-2,7-naphthyridin-3-yl]-4-methyl-3-pyridyl]amino]2,2-dimethylpropanoate

A solution of [[5-(6-amino-2,7-naphthyridin-3-yl)-4-methyl-3-pyridyl]-tert-butoxycarbonyl-amino]2,2-dimethylpropanoate (200 mg, 0.44 mmol), 2-bromo-6-isopropyl-5,8-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-7-one (180.82 mg, 0.66 mmol), cesium carbonate (432.96 mg, 1.33 mmol), 2-(di-tert-butylphosphino)-2′,4′,6′-triisopropyl-3,6-dimethoxy-1,1′-biphenyl (107.35 mg, 0.22 mmol), and t-BuBrettphos Pd-G3 (151.31 mg, 0.18 mmol) in 1,4-dioxane (20 mL) was stirred at 90° C. for 2 hrs. The resulting solution was concentrated under vacuum. The residue was purified by flash chromatography on silica gel, eluting with dichloromethane/methanol (10/1) to afford [tert-butoxycarbonyl-[5-[6-[(6-isopropyl-7-oxo-5,8-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-2-yl)amino]-2,7-naphthyridin-3-yl]-4-methyl-3-pyridyl]amino]2,2-dimethylpropanoate (150 mg, 0.23 mmol) as a yellow solid. LCMS (ESI) [M+H]⁺=643.

Step 4: 2-[[6-(5-amino-4-methyl-3-pyridyl)-2,7-naphthyridin-3-yl]amino]-6-isopropyl-5,8-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-7-one

To a solution of tert-butyl N-tert-butoxycarbonyl-N-[5-[6-[(6-isopropyl-7-oxo-5,8-dihydro-4H pyrazolo[1,5-d][1,4]diazepin-2-yl)amino]-2,7-naphthyridin-3-yl]-4-methyl-3-pyridyl]carbamate (150 mg, 0.23 mmol) in dichloromethane (5 mL) was added trifluoroacetic acid (1.0 mL) and the mixture was stirred at 25° C. for 1 h. The resulting solution was concentrated under vacuum. The residue was purified by Prep-HPLC (SunFire Prep C18 OBD, 19×150 mm 5 um; water (0.1% FA): CH₃CN=5%-23% B in 7 min) to afford 2-[[6-(5-amino-4-methyl-3-pyridyl)-2,7-naphthyridin-3-yl]amino]-6-isopropyl-5,8-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-7-one (58.7 mg, 0.13 mmol) as a yellow solid. LCMS (ESI) [M+H]⁺=443; ¹H NMR (400 MHz, DMSO-d₆) δ 9.72 (s, 1H), 9.26 (s, 1H), 9.20 (s, 1H), 8.01 (s, 1H), 7.92 (s, 1H), 7.80 (s, 1H), 7.70 (s, 1H), 6.05 (s, 1H), 5.63 (bs, 2H), 5.01 (s, 2H), 4.63-4.56 (m, 1H), 3.81-3.78 (m, 2H), 3.02-2.99 (m, 2H), 2.12 (s, 3H), 1.13 (d, J=6.8 Hz, 6H). Analytical HPLC retention time 1. 846 min, Method K.

Example 105 N-(6-(5-amino-4-methylpyridin-3-yl)-8-methyl-2,7-naphthyridin-3-yl)-5,6-dihydro-11H-imidazo[1,2-a]pyrazolo[1,5-d][1,4]diazepin-8-amine (Compound 105)

Synthesized following procedures similar to those described above according to the general synthetic methods. ¹HNMR (300 MHz, DMSO-d₆) δ 9.69 (s, 1H), 9.33 (s, 1H), 8.00 (s, 1H), 7.83 (s, 1H), 7.80 (s, 1H), 7.50 (s, 1H), 7.23 (s, 1H), 6.86 (s, 1H), 6.13 (s, 1H), 5.46 (s, 2H), 5.20 (s, 2H), 4.39-4.36 (m, 2H), 3.29-3.25 (m, 2H), 2.90 (s, 3H), 2.09 (s, 3H). Analytical HPLC retention time 1.269 min, Method K. MS (ESI) [M+H]⁺=438.2.

Example 106 2-((6-(5-amino-4-methylpyridin-3-yl)-8-methyl-2,7-naphthyridin-3-yl)amino)-6-isopropyl-5,6-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-7(8H)-one (Compound 106)

Synthesized following procedures similar to those described above according to the general synthetic methods. ¹HNMR (400 MHz, DMSO-d₆) δ 9.64 (s, 1H), 9.31 (s, 1H), 7.98 (s, 1H), 7.81 (s, 1H), 7.77 (s, 1H), 7.48 (s, 1H), 6.04 (s, 1H), 5.18 (s, 2H), 5.00 (s, 2H), 4.63-4.56 (m, 1H), 3.79 (t, J=5.6 Hz, 2H), 3.00 (t, J=5.6 Hz, 2H), 2.89 (s, 3H), 2.07 (s, 3H), 1.13 (d, J=6.8 Hz, 6H). Analytical HPLC retention time 1.862 min, Method K. MS (ESI) [M+H]⁺=457.2.

Example 107 2-((8-methoxy-6-(8-methyl-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazin-7-yl)-2,7-naphthyridin-3-yl)amino)-6-methyl-5,6-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-7(8H)-one (Compound 107)

Synthesized following procedures similar to those described above according to the general synthetic methods. ¹HNMR (400 MHz, DMSO-d₆) δ 9.60 (s, 1H), 9.10 (s, 1H), 7.67 (s, 1H), 7.54 (s, 1H), 7.19 (s, 1H), 6.05 (s, 1H), 5.65 (s, 1H), 5.00 (s, 2H), 4.30-4.28 (m, 2H), 4.01 (s, 3H), 3.85-3.83 (m, 2H), 3.36-3.31 (m, 2H), 3.10-3.00 (m, 2H), 2.94 (s, 3H), 2.14 (s, 3H). Analytical HPLC retention time 1.165 min, Method K. MS (ESI) [M+H]⁺=478.2.

Example 108 6-methyl-2-((8-methyl-6-(8-methyl-2,3-dihydro-1H-pyrido[2,3-b][1,4]oxazin-7-yl)-2,7-naphthyridin-3-yl)amino)-5,6-dihydro-4H-pyrazolo[1,5-d][1,4]diazepin-7(8H)-one (Compound 108)

Synthesized following procedures similar to those described above according to the general synthetic methods. ¹H NMR (400 MHz, DMSO-d₆) δ 9.61 (s, 1H), 9.29 (s, 1H), 7.73 (s, 1H), 7.50 (s, 1H), 7.43 (s, 1H), 6.06 (s, 1H), 5.61 (t, J=2.8 Hz, 1H), 5.01 (s, 2H), 4.28 (dd, J=5.1, 3.6 Hz, 2H), 3.88-3.79 (m, 2H), 3.36 (m, 2H), 3.07 (q, J=6.7, 5.7 Hz, 2H), 2.96 (s, 3H), 2.88 (s, 3H), 2.10 (s, 3H). MS (ESI) [M+H]⁺=471.3.

Example 109

Exemplary compounds were synthesized following procedures similar to those described above according to the general synthetic methods. The Compound (also abbreviated as “Cpd.” or “Compd.”) No. structure, name, HPLC analytical method, retention time (RT) and MS m/z are provided in Table A1.

TABLE A1 LCMS RT (min) Cpd. m/z No. Structure Name Method 109

6'-methyl-2'-((8-methyl-6-(8-methyl- 2,3-dihydro-1H-pyrido[2,3- b][1,4]oxazin-7-yl)-2,7-naphthyridin-3- yl)amino)-5',6'- dihydrospiro[cyclopropane-1,4'- pyrazolo[1,5-d][1,4]diazepin]-7'(8'H)- one  1.068 497.3 K 110

2-((6-(2-fluoro-6-methyl-4- ((methylamino)methyl)phenyl)-2,7- naphthyridin-3-yl)amino)-6-methyl-5,6- dihydro-4H-pyrazolo[1,5- d][1,4]diazepin-7(8H)-one  1.068 460.2 K 201

5-amino-N,N-dimethyl-2-((6-(4- methylpyridin-3-yl)-2,7-naphthyridin-3- yl)amino)isonicotinamide  2.74 400.2 N 202

6-(4-methylpyridin-3-yl)-N-(5- (methylsulfonyl)pyridin-2-yl)-2,7- naphthyridin-3-amine  3.22 392.2 N 203

6-((6-(4-methylpyridin-3-yl)-2,7- naphthyridin-3-yl)amino)pyridine-3- sulfonamide  2.99 352.2 N 204

N,N-dimethyl-6-((6-(4-methylpyridin-3- yl)-2,7-naphthyridin-3- yl)amino)nicotinamide  3.29 385.2 N 205

2-(6-((6-(4-methylpyridin-3-yl)-2,7- naphthyridin-3-yl)amino)pyridin-3- yl)acetonitrile  3.21 353.2 N 206

(6-((6-(4-methylpyridin-3-yl)-2,7- naphthyridin-3-yl)amino)pyridin-3- yl)methanol  3.03 344.2 N 207

N-methyl-6-((6-(4-methylpyridin-3-yl)- 2,7-naphthyridin-3-yl)amino)pyridine- 3-sulfonamide  3.07 358.2 N 208

2-(6-((6-(4-methylpyridin-3-yl)-2,7- naphthyridin-3-yl)amino)pyridin-3- yl)ethan-1-ol  3.18 358.2 N 209

6-cyclopropyl-N-(6-methylpyrimidin-4- yl)-2,7-naphthyridin-3-amine  2.039 278.2 N 210

6-methyl-N⁴-(6-(4-methylpyridin-3-yl)- 2,7-naphthyridin-3-yl)pyrimidine-2,4- diamine  1.889 344.1 N

BIOLOGICAL EXAMPLES

Exemplary compounds of Formula (I) were tested to assess compound inhibition of HPK-1. The K_(i) for each exemplary compound was determined

Example 1: HPK1-FL HTRF Enzymatic Assay (“HTRF”)

Assay Principle:

HPK-FL enzyme phosphorylates Biotin-SLP-76 substrate in the presence of ATP at 1 mM and varying concentrations of test compound. Product is detected by FRET using Eu-anti-pSLP76 Ab and SA-XL665. Also see www.cisbio.com/HTRF for additional HTRF technology information.

Instrumentation:

-   -   Echo555 compound dispenser     -   Agilent Bravo     -   Perkin Elmer Envision

Final Assay Conditions:

-   -   HPK full length, T165E S171E: 0.125 nM     -   Biotin-SLP76: 100 nM     -   ATP: 1 mM (ATP Km=20 μM)     -   Eu-anti-pSLP76: 2 nM     -   SA-XL665: 8.3 nM     -   Preincubation time: 30 min     -   Kinase reaction time: 60 min     -   Temperature: ambient     -   Total volume: 12 μl     -   ATP^(app) Km: 17.7 μM

Materials:

-   -   Assay plate: White ProxiPlate 384 F (PerkinElmer cat #6008289)     -   Kinase: HPK full length double mutant     -   Substrate: Biotin-SLP76     -   ATP: 100 mM ATP     -   BSG: 2% BSG     -   DMSO: DMSO (Sigma cat #34869-100ML)     -   Reaction Buffer: H₂O/50 mM HEPES, pH 7.5/10 mM MgCl₂/2 mM         TCEP/0.01% Brij-35/0.01% BSG     -   Detection mix: Eu-anti-pSLP76/SA-XL665 (Cisbio, #610SAXAC)

Assay Procedure K_(i) Determination:

To a 384 well Proxiplate with 80 nL compound or DMSO spotted on was added 4 μl/well kinase mix. The mixture was preincubated for 30 minutes and then 4 μl/well substrate mix was added. The solution was incubated for 60 min and then 4 μl/well detection mix was added. The solution was incubated for another 60 min. The plates were then loaded onto a Perkin Elmer Envision and the TR-FRET signal was measured at 615 and 665 nm. A ratio of 665/620 was used to calculate the % activity at each concentration of compound.

Example B2: HPK1 Lantha Binding Assay (“Lanth”)

Materials:

Reagent Vender-Cat# white ProxiPlate 384 F (assay plate) PerkinElmer-6008289 384-well Microplate (compound plate) Labcyte-LP-0200 HPK1 enzyme Signalchem-M23-11G Tracer-222 Invitrogen-PV6121 Eu-Anti-GST Ab Invitrogen-PV5594 Assay Buffer 2 mM DTT (Sigma-43815), 0.01% BRIJ-35 (Sigma-B4184), 10 mM MgCl₂, 50 mM HEPES (Invitrogen-15630130)

Procedure: I. Compound Dilution:

The compounds to be tested were diluted by preparing 12.5 uL/well of 5 mM compound (100×) in columns 2 and 13 and 10 ul/well of DMSO in columns 3-12, 14-23, and wells A1-H1 and I24-P24 of the compound plate using a Bravo liquid handling platform. For the reference compound, the top concentration was 1 mM. To the plate was added 10 ul 2 mM staurosporine in wells J1-P1 and A24-H24. A 11 point 5-fold compound serial dilution was performed using the Bravo liquid handling platform. From the plate were transferred 2.5 ul of the solutions from column 2 and column 13 to the 10 ul of DMSO in columns 3 and 14 & so on. The compound plate was centrifuged at 2500 rpm for 1 min. From the compound plate was transferred 80 nl of the compounds into an assay plate using the Echo liquid handler system. One compound plate makes two assay plates. Each assay plate is sealed and stored in an N₂ cabinet.

II. Assay Condition:

The following assay concentrations and times were used: 2 nM HPK1, 2 nM Eu-Anti-GST Ab, and 15 nM Tracer222, with 60 min incubation time.

III. HPK Lantha Binding Assay:

For the binding assay, 4 ul 2×HPK1 and Eu-anti-GST antibody were added to each well of the assay plate using a Multidrop reagent dispenser. The solutions were incubated in a 23 C incubator for 1 h. To each well of the assay plate was added 4 ul 2×Tracer-222 using a Multidrop reagent dispenser. The solutions were again incubated in a 23 C incubator for 1 h. The results of the assay were read using an Envision plate reader with the following parameters:TR_FRET, 340ex/615 and 665em; 100 usec Delay; and 200 usec integration.

IV. Analysis:

Compound Ki was analyzed using Morrison ki fit model in XL-fit

-   -   a.         fit=(1−((((E+x)+(Ki*(1+(S/Kd))))−(((((E+x)+(Ki*(1+(S/Kd)))){circumflex         over ( )}2)−((4*E)*x)){circumflex over ( )}0.5))/(2*E)))         -   res=(y-fit)     -   b. Parameters:         -   E=enzyme concentration         -   S=Tracer222 concentration, Kd=Tracer222 Kd         -   All measurements reported using the same units (uM)

Exemplary compounds were tested in the binding assays. The Ki values determined are listed in Table B1.

TABLE B1 HPK1 Ki (nM) Compd. No. H = HTRF, L = Lanth 101 0.27, H 102 4, H 103 0.39, L 104 2.3, H 105 0.85, H 106 2.5, H 107 2.1, H 108 0.66, H 109 0.03, H 110 13, H 201 463, H 202 291, H 204 24, L 206 577, H 207 11, L 208 28, L 209 >2000, H 210 3.9, L

Example B3: Human T-Cell IL2 Induction Assay Assay Principle:

Anti-CD3 and anti-CD28 activates TCR signaling in primary human pan T cells leading to IL-2 promoter induction. Secreted IL-2 in cell culture supernatant is detected by electrochemiluminescence using a capture antibody against IL-2 and an anti-IL-2 antibody labeled with SULFO-tag.

LITERATURE

See www.mesoscale.com for additional electrochemiluminescence technology information.

Assay Procedure:

Incubate primary human pan T cells with varying concentrations of test compounds for 30 minutes in a humidified incubator at 37° C. and 5% CO₂. Transfer cells to a plate pre-coated with a fixed concentration of anti-human CD3 (determined separately for each donor lot) and add soluble anti-human CD28 (final concentration=1 μg/ml). Stimulate cells in a humidified incubator at 37° C. and 5% CO₂ for 4 hours. Transfer 25 μl of supernatant to a MSD single spot plate pre-coated with an anti-human IL-2 antibody. Incubate MSD plate overnight at 4° C. with gentle shaking. Wash MSD plate 4× with wash buffer. Add SULFO-tagged detection antibody at a 1:50 dilution and incubate at room temperature shaking for 2 hours. Wash MSD plate 4× with wash buffer and add 150 μl 2×MSD read buffer. Read on an MSD instrument. Normalize data to stimulated/untreated controls to calculate % activity at each concentration of compound.

Materials:

-   -   Frozen Primary Human Pan-T Cells (StemCell Technologies #70024)     -   anti-human CD3 (OKT3 clone) (eBioscience #16-0037-81)     -   anti-human CD28 (CD28.2 clone) (BD #555725)     -   96-well Human IL-2 tissue culture kit (MSD #K151AHB-4)

Instrumentation:

-   -   Biomek FX for liquid handling (Beckman Coulter)     -   MSD SECTOR S 600 (Meso Scale Discovery)

Exemplary compounds of Formula (I) were tested in the human T-cell IL-2 induction assays. The % increase measured for IL-2 in cells treated by the test compounds relative to untreated cells are provided in Table B2 for certain compounds.

TABLE B2 % IL-2 Assayed Compound increase relative concentration No. to untreated cells (μM) 101 421% 0.31

It is to be noted that the term “a” or “an” entity refers to one or more of that entity; for example, “a polypeptide” is understood to represent one or more polypeptides. As such, the terms “a” (or “an”), “one or more,” and “at least one” can be used interchangeably herein.

All technical and scientific terms used herein have the same meaning. Efforts have been made to ensure accuracy with respect to numbers used (e.g. amounts, temperature, etc.) but some experimental errors and deviations should be accounted for.

Throughout this specification and the claims, the words “comprise,” “comprises,” and “comprising” are used in a non-exclusive sense, except where the context requires otherwise. It is understood that embodiments described herein include “consisting of” and/or “consisting essentially of” embodiments.

As used herein, the term “about,” when referring to a value is meant to encompass variations of, in some embodiments ±50%, in some embodiments ±20%, in some embodiments ±10%, in some embodiments ±5%, in some embodiments ±1%, in some embodiments ±0.5%, and in some embodiments ±0.10% from the specified amount, as such variations are appropriate to perform the disclosed methods or employ the disclosed compositions.

Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit, unless the context clearly dictates otherwise, between the upper and lower limit of the range and any other stated or intervening value in that stated range, is encompassed within the invention. The upper and lower limits of these small ranges which may independently be included in the smaller rangers is also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention.

Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. 

1. A compound of Formula (I)

or a pharmaceutically acceptable salt thereof, wherein: R¹ is hydrogen, halogen, hydroxyl, C₁₋₆ alkyl optionally substituted with halogen, C₃₋₄ cycloalkyl, or —O(C₁₋₆ alkyl) optionally substituted with halogen; R² is (i) or (ii): (i) a monocyclic 5- or 6-membered heteroaryl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰; or (ii) a polycyclic heteroaryl having the formula (a) or (b):

wherein the wavy line represents the attachment point to the parent structure, Q is CR²⁰, NR²¹, N, O or S; T is N or CR²²; Z¹ and Z² are independently N or C, provided at least one of Z¹ and Z² is C; T¹, T² and T³ are independently N or CR²³; ring A and ring B are independently a C₅₋₈ cycloalkyl or a 5- to 8-membered heterocycle having at least 3 ring-forming carbon atoms and 1, 2 or 3 ring-forming heteroatoms independently selected from the group consisting of N, P, O and S; wherein the C₅₋₈ cycloalkyl and the 5- to 8-membered heterocycle are independently optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰; and wherein two substituents of the C₅₋₈ cycloalkyl or the 5- to 8-membered heterocycle, where present, optionally taken together form a spiro, fused or bridged cycloalkyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰ or a sprio, fused or bridged heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰; R²⁰, R²¹, R²² and R²³ are each independently hydrogen or R¹⁰; R³ is hydrogen, halogen, cyano, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, 3- to 14-membered heterocyclyl, or —OR⁷; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl and 3- to 14-membered heterocyclyl of R³ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰; R⁴ is C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl, 3- to 14-membered heterocyclyl, halogen, cyano, —C(O)R⁶, —C(O)OR⁷, —C(O)NR^(8a)R^(8b), —OR⁷, —OC(O)R⁶, —OC(O)NR^(8a)R^(8b), —SR⁷, —S(O)R⁹, —S(O)₂R⁹, —S(O)₂NR^(8a)R^(8b), —P(O)R^(9a)R^(9b), —NR^(8a)R^(8b), —N(R⁸)C(O)R⁶, —N(R⁸)C(O)OR⁷, —N(R⁸)C(O)NR^(8a)R^(8b), —N(R⁸)S(O)₂R⁹, or —N(R⁸)S(O)₂NR^(8a)R^(8b); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R⁴ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰; each R⁶ is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆-10 aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁶ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰; each R⁷ is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁷ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰; each R^(g) is independently hydrogen or C₁₋₆ alkyl; each R^(8a) and R^(8b) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(8a) and R^(8b) are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰; or R^(8a) and R^(8b) are taken together with the nitrogen atom to which they are attached to form a 4- to 12-membered heterocyclyl optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰; each R⁹ is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R⁹ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰; each R^(9a) and R^(9b) is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl, 3- to 12-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 14-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(9a) and R^(9b) are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰; or R^(9a) and R^(9b) are taken together with the phosphorus atom to which they are attached to form a 4- to 12-membered heterocyclyl optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰; each R¹⁰ is independently oxo, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 12-membered heterocyclyl, halogen, cyano, —C(O)R^(a), —C(O)OR^(b), —C(O)NR^(c)R^(d), —OR^(b), —OC(O)R^(a), —OC(O)NR^(c)R^(d), —SR^(b), —S(O)R^(e), —S(O)₂R^(e), —S(O)(═NH)R^(e), —S(O)₂NR^(c)R^(d), —NR^(c)R^(d), —N(R^(f2))C(O)R^(a), —N(R^(f2))C(O)OR^(b), —N(R^(f2))C(O)NR^(c)R^(d), —N(R^(f2))S(O)₂R^(e), —N(R^(f2))S(O)₂NR^(c)R^(d), or —P(O)R^(g)R^(h); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R¹⁰ are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹; each R^(a) is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆-10 aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(a) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹; each R^(b) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(b) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹; each R^(C) and R^(d) is independently hydrogen, C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R and R^(d) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹; or R^(C) and R^(d) are taken together with the nitrogen atom to which they are attached to form a 4- to 12-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹; each R^(e) is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 12-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(e) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹; each R is independently hydrogen or C₁₋₆ alkyl; each R^(g) and R^(h) is independently C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 12-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 12-membered heterocyclyl of R^(g) and R^(h) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹; or R^(g) and R^(h) are taken together with the phosphorus atom to which they are attached to form a 4- to 12-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹¹; each R¹¹ is independently oxo, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 8-membered heterocyclyl, halogen, cyano, —C(O)R^(a1), —C(O)OR^(b1), —C(O)NR^(c1)R^(d1), —OR^(b1), —OC(O)R^(a1), —OC(O)NR^(c1)R^(d1), —SR^(b1), —S(O)R^(e1), —S(O)₂R^(e1), —S(O)₂NR^(c1)R^(d1), —NR^(c1)R^(d1), —N(R^(f1))C(O)R^(a1), —N(R^(f1))C(O)OR^(b1), —N(R^(f1))C(O)NR^(c1)R^(d1), —N(R^(f1))S(O)₂R^(e1), —N(R^(f1))S(O)₂NR^(e1)R^(d1), or —P(O)R^(g1)R^(h1); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R¹¹ are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²; each R^(a1) is independently hydrogen, C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₆ cycloalkyl, C₆-10 aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(a) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²; each R^(b1) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(b1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²; each R^(c1) and R^(d1) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(c1) and R^(d1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²; or R^(c1) and R^(d1) are taken together with the nitrogen atom to which they are attached to form a 4- to 8-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²; each R^(e1) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(e) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²; each R¹ is independently hydrogen or C₁₋₆ alkyl; each R^(g) and R^(h1) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl, 3- to 8-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 3- to 8-membered heterocyclyl of R^(g) and R^(h1) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²; or R^(g1) and R^(h1) are taken together with the phosphorus atom to which they are attached to form a 4- to 8-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹²; each R¹² is independently oxo, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl, 3- to 6-membered heterocyclyl, halogen, cyano, —C(O)R^(a2), —C(O)OR^(b2), —C(O)NR^(c2)R^(d2), —OR^(b2), —OC(O)R^(a2), —OC(O)NR^(c2)R^(d2), —S(O)₂R^(e2), —S(O)₂NR^(c2)R^(d2), —NR^(c2)R^(d2), —N(R^(f2))C(O)R^(a2), —N(R^(f2))C(O)OR^(b2), —N(R^(f2))C(O)NR^(c2)R^(d2), —N(R^(f2))S(O)₂R^(e2), —N(R^(f2))S(O)₂NR^(c2)R^(d2), or —P(O)R^(g2)R^(h2); wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R¹² are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³; each R^(a2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R^(a2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³; each R^(b2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl and 3- to 6-membered heterocyclyl of R^(b2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³; each R^(e2) and R^(d2) is independently hydrogen, C₁₋₆ alkyl, C₃₋₆ cycloalkyl or 3- to 8-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl and 3- to 8-membered heterocyclyl of R^(e2) and R^(a2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³; or R^(e2) and R^(d2) are taken together with the nitrogen atom to which they are attached to form a 4- to 6-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³; each R^(e2) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl or 3- to 6-membered heterocyclyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆ aryl, 5- to 6-membered heteroaryl and 3- to 6-membered heterocyclyl of R^(e2) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³; each R is independently hydrogen or C₁₋₆ alkyl; each R^(g)2 and R^(h) is independently C₁₋₆ alkyl, C₃₋₆ cycloalkyl, 3- to 8-membered heterocyclyl, or —O—C₁₋₆ alkyl; wherein the C₁₋₆ alkyl, C₃₋₆ cycloalkyl, and 3- to 8-membered heterocyclyl of R^(g2) and R^(h) are each optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³; or R^(g2) and R¹¹ are taken together with the phosphorus atom to which they are attached to form a 4- to 6-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹³; and each R¹³ is independently oxo, halogen, hydroxyl, —O(C₁₋₆ alkyl), cyano, C₁₋₆ alkyl or C₁₋₆ haloalkyl.
 2. The compound of claim 1, wherein R¹ is hydrogen, hydroxy, —O(C₁₋₆ alkyl), or C₁₋₆ alkyl optionally substituted with cyano.
 3. (canceled)
 4. (canceled)
 5. The compound of claim 1, wherein R³ is hydrogen or halogen.
 6. The compound of claim 1, wherein R⁴ is C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl, 3- to 14-membered heterocyclyl, halogen, cyano, —C(O)R⁶, —C(O)OR⁷, —OC(O)R⁶, —OC(O)NR^(8a)R^(8b), —SR⁷, —S(O)R⁹, —S(O)₂R⁹, —S(O)₂NR^(8a)R^(8b), —NR^(8a)R^(8b), —N(R⁸)C(O)R⁶, —N(R⁸)C(O)OR⁷, —N(R⁸)C(O)NR^(8a)R^(8b), —N(R⁸)S(O)₂R⁹, or —N(R⁸)S(O)₂NR^(8a)R^(8b); wherein the C₁₋₆ alkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R⁴ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰.
 7. (canceled)
 8. (canceled)
 9. The compound of claim 1, wherein R⁴ is C₆₋₁₀ aryl, 5- to 10-membered heteroaryl or 5- to 6-membered heterocyclyl; wherein the C₆₋₁₀ aryl, 5- to 10-membered heteroaryl and 5- to 6-membered heterocyclyl of R⁴ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰.
 10. The compound of claim 9, wherein R⁴ is

wherein the wavy line represents the attachment point to the parent structure, R^(4a), R^(4b) and R^(4c) are each independently hydrogen or R¹⁰, or two vicinal R^(4(a-c)) are taken together with the atoms to which they are attached form a fused 5- or 6-membered heteroaryl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰ or a fused 5- or 6-membered heterocyclyl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰.
 11. (canceled)
 12. (canceled)
 13. The compound of claim 9, wherein R⁴ is


14. (canceled)
 15. The compound of claim 1, wherein R² is a polycyclic heteroaryl having the formula (a) or (b):


16. (canceled)
 17. The compound of claim 15, wherein R² is a polycyclic heteroaryl having the formula (a):


18. The compound of claim 17, wherein R² is

wherein q is 0, 1, 2, 3, 4, 5 or 6; Y is C₁₋₄ alkylene wherein optionally one or more of the carbon atoms of the C₁₋₄ alkylene are replaced by a heteroatom selected from oxygen, sulfur and nitrogen, and the C₁₋₄ alkylene is optionally substituted with R¹⁰; R²⁴ is independently hydrogen or R¹⁰.
 19. (canceled)
 20. (canceled)
 21. The compound of claim 17, wherein R² is

wherein X is CH₂, N, O or S; n is 1, 2, 3 or 4; p is 0, 1, 2, 3 or 4; R²⁴ is hydrogen or R¹⁰.
 22. (canceled)
 23. (canceled)
 24. (canceled)
 25. The compound of claim 17, wherein R² is

wherein q is 0, 1, 2, 3, 4, 5 or 6; G is independently C or N; G′ is independently N, NR²⁸, CR²⁹, S or 0; R²⁸ and R²⁹ are independently hydrogen or R¹¹; or two vicinal groups R²⁸ and R²⁹ are taken together to form a 5- to 6-membered heterocyclyl.
 26. (canceled)
 27. The compound of claim 17, wherein R² is selected from the group consisting of


28. The compound of claim 1, wherein R² is a monocyclic 5- or 6-membered heteroaryl optionally substituted with 1, 2, 3 or 4 substituents independently selected from R¹⁰.
 29. (canceled)
 30. (canceled)
 31. The compound of claim 28, wherein R² is

wherein the wavy line represents the attachment point to the parent structure, R^(2a), R^(2b), R^(2c) and R^(2d) are each independently hydrogen or R¹⁰.
 32. (canceled)
 33. (canceled)
 34. (canceled)
 35. The compound of claim 28, wherein R⁴ is C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl or 3- to 14-membered heterocyclyl; wherein the C₃₋₈ cycloalkyl, C₆₋₁₄ aryl, 5- to 14-membered heteroaryl and 3- to 14-membered heterocyclyl of R⁴ are each optionally substituted with 1, 2, 3, 4 or 5 substituents independently selected from R¹⁰.
 36. The compound of claim 1, wherein the compound is selected from the group consisting of Compound Nos. 101-110 and 201-210 in Table 1, or a pharmaceutically acceptable salt thereof.
 37. (canceled)
 38. A pharmaceutical composition comprising the compound of claim 1, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient.
 39. (canceled)
 40. A method of inhibiting HPK1, said method comprising contacting HPK1 in a subject with an effective amount of the compound of claim 1, or a pharmaceutically acceptable salt thereof.
 41. A method for enhancing an immune response in a subject in need thereof, wherein the method comprises administering to said subject an effective amount of the compound of claim 1, or a pharmaceutically acceptable salt thereof.
 42. (canceled)
 43. A method for treating a HPK1-dependent disorder, said method comprising administering to a subject in need thereof an effective amount of the compound of claim 1, or a pharmaceutically acceptable salt thereof.
 44. The method of claim 43, wherein said HPK1-dependent disorder is a cancer.
 45. (canceled)
 46. (canceled)
 47. (canceled)
 48. (canceled)
 49. (canceled) 